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JP2006261809

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DESCRIPTION JP2006261809
[PROBLEMS] To provide a sound quality adjustment device and a sound quality adjustment
method capable of sound quality adjustment in which an instruction content of sound quality
adjustment input by an operator and a sound quality change (psycho-acoustic sense) felt by the
operator are matched. SOLUTION: A sound quality adjustment apparatus 1 is operated by an
operator, and an operation input unit 5 into which an instruction content of sound quality
adjustment including the enhancement amount or attenuation amount of an input audio signal is
input, and an equalizer for amplifying an audio signal. The control microcomputer 7 controls the
equalizer unit 3 based on the instruction content input from the operation input unit 5. When the
control microcomputer 7 amplifies the selected frequency band selected by the operator, the
reduction amount of the sound pressure energy of the sound signal when the selected frequency
band is attenuated increases the sound frequency of the sound signal when the selected
frequency band is enhanced. The reduction rate of the sound pressure level is set to a value
larger than the increase rate so as to be larger than the increase amount of pressure energy.
[Selected figure] Figure 1
Tone control device and tone control method
[0001]
The present invention relates to a sound quality adjustment device for adjusting the sound
quality of an audio signal to be output and a sound quality adjustment method implemented by
the sound quality adjustment device, such as a tone controller or graphic equalizer mounted in
audio equipment.
[0002]
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1
A sound quality adjustment device such as a tone controller or graphic equalizer is a device that
increases or decreases the sound pressure level of a predetermined frequency band of an input
audio signal based on the sound quality adjustment content input by the operator.
In a typical conventional tone control apparatus, when an operator operates, for example, a tone
control knob to input an increase or a decrease in sound pressure level as an instruction content
of the tone control, a predetermined frequency band of the input audio signal The sound
pressure level is increased or decreased by the sound pressure level amount obtained based on
the input amount of increase or the amount of attenuation and output. The sound pressure level
amount to be changed is determined by the product of the input amount of increase and the
predetermined increase rate or the product of the input amount of attenuation and the
predetermined decrease rate. The rate of increase and the rate of decrease are set to the same
value.
[0003]
In addition, there is also a sound quality adjustment device that increases and decreases sound
pressure levels of a plurality of frequency bands of an input audio signal and outputs the sound
pressure levels. When the sound quality adjustment device inputs the frequency band that the
operator wants to change as the sound quality adjustment instruction content and the amount of
increase or decrease of the sound pressure level, the sound pressure level of the specified
frequency band in the input audio signal Is output by increasing or decreasing the sound
pressure level amount obtained based on the input amount of enhancement or attenuation. As
described above, the sound pressure level to be changed is determined by the product of the
input enhancement amount and the predetermined increase rate or the product of the input
attenuation amount and the predetermined decrease rate. The rate of increase and the rate of
decrease are set to the same value in all frequency bands.
[0004]
In addition, in order to perform sound quality adjustment more effectively, a technology has been
proposed that performs sound quality adjustment in consideration of human psychoacoustic
sense. For example, Patent Document 1 generates a signal having a harmonic series for each
fundamental frequency in a low frequency range, so as to substantially achieve the loudness
08-05-2019
2
matching attribute of the residual harmonic signal and the low frequency signal. A bass
enhancement method is disclosed that applies loudness matching to the residual harmonic
signals to efficiently give the listener a pseudo low frequency psychoacoustic sensation. Japanese
Patent Publication No. 2000-505277
[0005]
According to psychoacoustics, when a sound signal whose sound quality is adjusted by the sound
quality adjustment device is reproduced (sounded), the sound pressure increases or decreases
when the sound pressure level in a certain frequency band is increased or decreased in the
human audio frequency band. Even if the level amount is the same, the sound pressure level felt
by humans when the sound pressure level is lowered is smaller than the sound pressure level felt
by humans when the sound pressure level is raised. It is known. In a typical conventional tone
control system, the rate of increase and the rate of decrease when changing the sound pressure
level in a certain frequency band are set to the same value, so the amount of increase and the
amount of attenuation input by the operator are Even in the case of the same, in the
psychoacoustic sense of the operator, the lowering degree of the sound pressure level is felt to be
smaller than the rising degree of the sound pressure level.
[0006]
According to psychoacoustics, for example, in a frequency band centered on 1 kilohertz (referred
to as 1 kilohertz band), human hearing is known to be most sensitive to changes in sound
pressure level. On the other hand, frequency bands lower than 1 kilohertz band (for example,
frequency bands centering on 250 or 500 hertz) and frequency bands higher than 1 kilohertz
band (for example, center frequency on 2 kilohertz or 4 kilohertz) In), human hearing is
insensitive to changes in sound pressure level compared to the 1 kHz band (reference: RobinsonDadson curve). In a typical conventional tone control device, the rate of change (rate of increase
and rate of decrease) when changing the sound pressure level is set to the same value in all
frequency bands, so for example, the amount of increase input by the operator Even in the same
case, the operator may feel that the rise in sound pressure level in bands other than the 1
kilohertz band is smaller than the rise in sound pressure level in the 1 kilohertz band.
[0007]
As described above, in the conventional sound quality adjustment device, the difference between
the sound quality adjustment instruction content (the amount of increase or the attenuation
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amount and the frequency band) inputted by the operator and the sound quality change
(psychoacoustic sense) which the operator actually feels There is a problem that will occur.
[0008]
In addition, although the sound quality adjustment taking into consideration the psychoacoustic
sense is performed in Patent Document 1 described above, the technique described in Patent
Document 1 is a technique for improving the psychoacoustic sense for low frequencies. It is not a
technique to improve the psychoacoustic sense of changes in sound pressure level.
[0009]
An object of the present invention is to provide a sound quality adjustment device and a sound
quality adjustment method capable of performing sound quality adjustment in which the
instruction content of sound quality adjustment input by the operator and the psychoacoustic
sense are matched.
[0010]
The invention according to claim 1 is a sound quality adjustment device for enhancing or
attenuating a predetermined frequency band of an input audio signal, comprising: input means to
which an augmentation or attenuation instruction for the predetermined frequency band is input;
A sound quality adjustment device characterized by enhancing or attenuating the predetermined
frequency band based on an instruction input from an input means, and setting the decreasing
rate at the time of attenuation to a value larger than the increasing rate at the time of enhancing.
is there.
[0011]
The invention according to claim 9 is a sound quality adjustment method for enhancing or
attenuating a predetermined frequency band of an input audio signal, wherein the predetermined
frequency band is determined based on an instruction to increase or attenuate the predetermined
frequency band. Is set to a value larger than the increase rate at the time of increase, and the
decrease rate at the time of decrease is set to a value larger than the increase rate at the time of
increase.
[0012]
According to the present invention, when the operator inputs an augmentation or attenuation
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instruction from the input means, a predetermined frequency band of the input audio signal is
enhanced or attenuated based on the instruction content and outputted.
In the present invention, since the reduction rate at the time of attenuation of the audio signal is
set to a value larger than the increase rate at the time of enhancement, the sound pressure
energy is increased even when the amount of enhancement input by the operator and the
amount of attenuation are the same. The amount of energy reduction is larger than the amount
of energy.
In this way, even if the amount of increase and the amount of attenuation input by the operator
are the same, the amount of reduced energy when attenuating the audio signal is larger than the
amount of increased energy when it is enhanced. In the psychoacoustic sense, the rise and fall of
the sound pressure level are felt to the same extent.
[0013]
In the inventions according to claims 2 and 10, a plurality of predetermined frequency bands are
provided, and the reduction rate and the increase rate can be set for each frequency band while
enhancing or attenuating each frequency band. It is characterized.
[0014]
According to the present invention, when the operator inputs from the input means the type of
frequency band to be amplified and the augmentation or attenuation instruction, the designated
frequency band in the inputted audio signal is boosted or attenuated and outputted.
There may be only one type of frequency band, two or more types, or all types.
In the present invention, the reduction rate and the increase rate can be set for each frequency
band.
[0015]
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5
For example, if the rate of increase in the low frequency band and the rate of increase in the high
frequency band are set to a value larger than the rate of increase in the standard frequency band,
sound is obtained even if the amount of enhancement in each frequency band input by the
operator is the same. With regard to pressure energy, the amount of energy increase in the low
frequency band and the amount of energy increase in the high frequency band are larger than
the amount of energy increase in the standard frequency band.
Thus, even if the amount of increase in each frequency band input by the operator is the same,
the amount of increased energy when increasing the low frequency band and the high frequency
band is the amount of increased energy when increasing the standard frequency band. As it
becomes larger than the above, in the operator's psychoacoustic sense, the sound pressure level
rising in the three frequency bands of the low frequency band, the standard frequency band and
the high frequency band can be felt to the same extent .
[0016]
Further, if the reduction rate in the low frequency band and the reduction rate in the high
frequency band are set to values larger than the reduction rates in the standard frequency band,
even if the attenuation amount of each frequency band input by the operator is the same, With
regard to pressure energy, the reduced energy amount in the low frequency band and the
reduced energy amount in the high frequency band are larger than the reduced energy amount
in the standard frequency band.
Thus, even if the attenuation amount of each frequency band input by the operator is the same,
the reduced energy amount when attenuating the low frequency band and the high frequency
band is the reduced energy amount when attenuating the standard frequency band As it becomes
larger than this, in the psychoacoustic sense of the operator, the degree of decrease in sound
pressure level in the three frequency bands of the low frequency band, the standard frequency
band and the high frequency band can be felt to the same extent .
[0017]
The inventions according to claim 3 and claim 11 are characterized in that the increase rate and
the decrease rate are set so as to increase as the frequency becomes lower. According to the
present invention, the rate of increase in each of the plurality of frequency bands is set to a
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larger value as the frequency band becomes lower, so the frequency for sound pressure energy is
obtained even if the amount of increase input by the operator is the same. The lower the band is,
the greater the amount of energy increase. In this way, even if the amount of enhancement input
by the operator is the same, the amount of increased energy when enhancing the frequency band
is larger in the lower frequency band, so the psychoacoustic sense of the operator In the above,
sound pressure level rising in a plurality of frequency bands can be felt to the same extent. In
addition, the respective reduction rates in a plurality of frequency bands are also set to a larger
value as the frequency becomes lower, so even if the attenuation amount input by the operator is
the same, the sound pressure energy has a low frequency band. The amount of energy reduction
is larger. As described above, even if the amount of attenuation input by the operator is the same,
the amount of reduced energy when attenuating the frequency band is larger in the lower
frequency band, so the psychoacoustic feeling of the operator In the above, the degree of
decrease in sound pressure level in a plurality of frequency bands is felt to the same extent.
[0018]
The inventions according to claim 4 and claim 12 are characterized in that the increase rate and
the decrease rate are set so as to increase as the frequency becomes higher. According to the
present invention, when there are a plurality of frequency bands, the rate of increase in each of
the plurality of frequency bands is set to a larger value as the frequency band becomes higher, so
even if the amount of increase input by the operator is the same. With regard to sound pressure
energy, the amount of energy increase is larger in the higher frequency band. Thus, even if the
amount of increase input by the operator is the same, the amount of increased energy when
increasing the frequency band is larger in the high frequency band, so the psychoacoustic sense
of the operator In the above, sound pressure level rising in a plurality of frequency bands can be
felt to the same extent. In addition, the respective reduction rates in a plurality of frequency
bands are also set to larger values as the frequency band becomes higher, so that even if the
attenuation amount input by the operator is the same, the sound pressure energy has a high
frequency band. The amount of energy reduction is larger. As described above, even if the
amount of attenuation inputted by the operator is the same, the amount of reduced energy when
the frequency band is attenuated becomes larger in the high frequency band, so that the
psychoacoustic feeling of the operator In the above, the degree of decrease in sound pressure
level in a plurality of frequency bands is felt to the same extent.
[0019]
The invention according to claim 5 is a sound quality adjustment device for enhancing or
attenuating a predetermined frequency band of an input audio signal, comprising: input means to
which an augmentation or attenuation instruction for the predetermined frequency band is input,
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According to an instruction input from an input unit, the predetermined frequency band is
enhanced or attenuated, and the attenuation Q value is set to a value smaller than the
enhancement Q value.
[0020]
The invention according to claim 13 is a sound quality adjustment method for enhancing or
attenuating a predetermined frequency band of an input audio signal, wherein the predetermined
frequency band is determined based on an increase or attenuation instruction for the
predetermined frequency band. , And setting the attenuation Q value to a value smaller than the
enhancement Q value.
[0021]
According to the present invention, when the operator inputs an augmentation or attenuation
instruction from the input means, a predetermined frequency band of the input audio signal is
enhanced or attenuated based on the instruction content and outputted.
In the present invention, since the attenuation Q value is set to a value smaller than the
enhancement Q value, the sound pressure energy decreases more than the increase energy
amount even if the amount of enhancement input by the operator is the same as the amount of
attenuation. The amount of energy is greater.
As described above, even if the amount of increase and the amount of attenuation input by the
operator are the same, the amount of decrease in sound pressure energy when the sound signal
is attenuated is larger than the amount of increase when the sound signal is increased. In the
psychoacoustic sense of, the rise and fall of the sound pressure level are felt to the same extent.
[0022]
In the invention according to claims 6 and 14, a plurality of predetermined frequency bands are
provided, and the attenuation Q value and the enhancement Q value can be set for each
frequency band while enhancing or attenuating each frequency band. It is characterized by being.
[0023]
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8
According to the present invention, when the operator inputs from the input means the type of
frequency band to be amplified and the augmentation or attenuation instruction, the designated
frequency band in the inputted audio signal is boosted or attenuated and outputted.
Only one type, two or more types, or all types of frequency band may be input. In the present
invention, the attenuation Q value and the enhancement Q value can be set for each frequency
band.
[0024]
For example, if the enhancement Q value in the low frequency band and the enhancement Q
value in the high frequency band are set to a value smaller than the enhancement Q value in the
standard frequency band, the enhancement amount of each frequency band input by the
operator Even in the same case, with regard to the sound pressure energy, the increased energy
amount in the low frequency band and the increased energy amount in the high frequency band
are larger than the increased energy amount in the standard frequency band. Thus, even if the
amount of increase in each frequency band input by the operator is the same, the amount of
increased energy when increasing the low frequency band and the high frequency band is
greater than the amount of increased energy when increasing the standard frequency band. In
the psycho-acoustic sense of the operator, the sound pressure levels of the three frequency
bands, ie, the low frequency band, the standard frequency band and the high frequency band, are
felt to rise to the same extent.
[0025]
Also, if the attenuation Q value in the low frequency band and the attenuation Q value in the high
frequency band are set to values smaller than the attenuation Q value in the standard frequency
band, the attenuation amount of each frequency band input by the operator Even in the same
case, for sound pressure energy, the amount of energy reduction in the low frequency band and
the amount of energy reduction in the high frequency band are larger than the amount of energy
reduction in the standard frequency band. Thus, even if the amount of attenuation in each
frequency band input by the operator is the same, the amount of reduced energy when
attenuating the low frequency band and the high frequency band is smaller than the amount of
energy when the standard frequency band is attenuated In the psycho-acoustic sense of the
08-05-2019
9
operator, the degree of decrease in sound pressure level in the three frequency bands of the low
frequency band, the standard frequency band and the high frequency band can be felt to the
same extent.
[0026]
The inventions according to claims 7 and 15 are characterized in that the enhancement Q value
and the attenuation Q value are set so as to become smaller values as the frequency becomes
lower. According to the present invention, when there are a plurality of frequency bands, the
respective enhancement Q values in the plurality of frequency bands are set to smaller values as
the frequency band becomes lower, so that the amount of enhancement input by the operator is
the same. Even in the case of sound pressure energy, the amount of energy increase is larger in
the lower frequency band. As described above, even if the amount of increase input by the
operator is the same, the increase in the amount of energy when increasing the frequency band
is larger in the lower frequency band. In the above, sound pressure level rising in a plurality of
frequency bands can be felt to the same extent. In addition, since the attenuation Q values in a
plurality of frequency bands are also set to larger values as the frequency band becomes lower,
the frequency for sound pressure energy is low even if the amount of attenuation input by the
operator is the same. The amount of energy reduction is larger in the band. As described above,
even if the amount of attenuation inputted by the operator is the same, the reduced energy
amount when attenuating the frequency band is larger in the lower frequency band, and thus the
psychoacoustic feeling of the operator In the above, the degree of decrease in sound pressure
level in a plurality of frequency bands is felt to the same extent.
[0027]
The inventions according to claims 8 and 16 are characterized in that the enhancement Q value
and the attenuation Q value are set so as to become smaller values as the frequency becomes
higher. According to the present invention, in the case where there are a plurality of frequency
bands, the respective enhancement Q values in the plurality of frequency bands are set to smaller
values as the frequency band becomes higher, so the amount of enhancement input by the
operator is the same. Even in the case of sound pressure energy, the amount of energy increase
is larger in the higher frequency band. As described above, even if the amount of increase input
by the operator is the same, the higher the frequency band is, the larger the amount of increased
energy when the frequency band is increased. Therefore, the psychoacoustic feeling of the
operator In the above, sound pressure level rising in a plurality of frequency bands can be felt to
the same extent. In addition, since the attenuation Q values in a plurality of frequency bands are
08-05-2019
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also set to smaller values as the frequency band becomes higher, the frequency for sound
pressure energy is high even if the amount of attenuation input by the operator is the same. The
amount of energy reduction is larger in the band. As described above, even if the amount of
attenuation input by the operator is the same, the higher the frequency band is, the larger the
amount of reduced energy when the frequency band is attenuated. Therefore, the psychoacoustic
feeling of the operator In the above, the degree of decrease in sound pressure level in a plurality
of frequency bands is felt to the same extent.
[0028]
According to the present invention, it is possible to perform the sound quality adjustment in
which the instruction content of the sound quality adjustment input by the operator and the
sound quality change (psycho-acoustic sense) which the operator actually feels are matched. By
this, it is possible to easily perform sound quality adjustment adapted to human hearing.
Therefore, even an operator who is unfamiliar with the operation can easily perform sound
quality adjustment adapted to human hearing.
[0029]
First Embodiment Hereinafter, a first embodiment of the present invention will be described with
reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing the configuration of the sound
quality adjustment device 1 according to the first embodiment of the present invention, and FIG.
2 is a plan view showing the appearance of the sound quality adjustment device 1. The sound
quality adjustment apparatus 1 is mounted on an audio device including, for example, a reading
device 10 that reads out an audio signal recorded in a recording medium, a tuner 11 that
receives and demodulates radio waves including the audio signal, and a speaker 12. Ru. The
sound quality adjustment device 1 is a device that adjusts the sound quality of an audio signal
read by the reading device 10 and an audio signal demodulated by the tuner 11, and is realized
by, for example, a sound quality adjustment device such as a tone controller or graphic equalizer.
. The recording medium on which the audio signal is recorded is not only the compact disc (CD),
the mini disc (MD) and the hard disc (HDD) shown in FIG. 1, but also, for example, a digital
versatile disc (DVD) Good.
[0030]
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The sound quality adjustment apparatus 1 includes an input selection unit 2, an equalizer unit 3,
an amplifier 4, an operation input unit 5, a display unit 6, a control microcomputer 7, and a
coefficient storage unit 8. The input selection unit 2 selects any one of the reading device 10 and
the tuner 11, inputs an audio signal output from the selected one, and supplies the audio signal
to the equalizer unit 3.
[0031]
The equalizer unit 3 spectrum-analyzes the audio signal from the input selection unit 2, amplifies
a predetermined frequency band in the audio signal, and supplies the amplified signal to the
amplifier 4. The amplifier 4 amplifies the audio signal amplified by the equalizer unit 3 and
supplies the amplified audio signal to the speaker 12.
[0032]
The operation input unit 5, which is an input means, is operated by the operator and receives the
sound quality adjustment content including the amount of increase or attenuation of the sound
pressure level of the input audio signal and the type of frequency band to be amplified. The
contents are given to the control microcomputer 7. Specifically, as shown in FIG. 2, the operation
input unit 5 includes an UP button 5a, a DOWN button 5b, and two frequency switching buttons
5c and 5d.
[0033]
The frequency switching buttons 5c and 5d are buttons operated to select a frequency band to
be amplified from among a plurality of frequency bands, and amplification is performed by
selecting one center frequency from center frequencies of the respective frequency bands. The
desired frequency band is selected. Here, the center frequencies of the plurality of frequency
bands are 250 Hz, 1 kHz, and 4 kHz. The frequency band centered at 1 kilohertz is the standard
frequency band (represented by "Mid" in FIG. 3), and the frequency band centered at 250 hertz
lower than 1 kilohertz is the low frequency band (FIG. 3 " A frequency band having a center
frequency of 4 kilohertz higher than 1 kilohertz as a high frequency band (represented by "Treb"
in FIG. 3). In the initial state, for example, a center frequency centrally located among a plurality
of center frequencies, here, 1 kilohertz is selected.
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[0034]
When the operator presses one of the frequency switching buttons 5c, a command for selecting a
center frequency one step lower than the center frequency selected at that time is given to the
control microcomputer 7. For example, when the frequency switching button 5c is pressed in an
initial state in which 1 kHz is selected as the center frequency, a command to select 250 Hz as
the center frequency is given to the control microcomputer 7.
[0035]
When the operator presses the other frequency switching button 5d, a command to select a
center frequency one step higher than the center frequency selected at that time is given to the
control microcomputer 7. For example, when the frequency switching button 5d is pressed in the
initial state in which 1 kHz is selected as the center frequency, a command to select 4 kHz as the
center frequency is given to the control microcomputer 7.
[0036]
The UP button 5a and the DOWN button 5b are buttons operated to input an increase amount or
an attenuation amount when amplifying a frequency band including the selected center
frequency (hereinafter, referred to as a selected frequency band). In the initial state, the amount
of increase or the amount of attenuation is set to “0”, for example. When the operator presses
the UP button 5a from the initial state, a command to increase the selected frequency band by
one step (sometimes referred to as "1 step") is given to the control microcomputer 7. To increase
the sound pressure level in the frequency band by the amount of increase obtained based on the
predetermined increase rate is to increase the level by one step. The increase rate is a numerical
value indicating the amount of increase in sound pressure level in each step. Therefore, each time
the operator presses the UP button 5a, the number of steps for increasing the selected frequency
band (increase amount) increases by one as 0 → + 1 step → + 2 step → + 3 step →. Here, “+”
is a symbol indicating that the frequency band is to be enhanced.
[0037]
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Also, when the operator presses the DOWN button 5b from the initial state, a command to
attenuate the selected frequency band in the input audio signal by one step is given to the
control microcomputer 7. Attenuation by one step means to decrease the sound pressure level in
the frequency band by an increase amount obtained based on a predetermined decrease rate.
The decrease rate is a numerical value indicating the amount of decrease in sound pressure level
in each step. Therefore, each time the operator presses the DOWN button 5b, the number of
steps (attenuation amount) to attenuate the selected frequency band decreases by one as 0 → -1
step → -2 step → -3 step ... . Here, "-" is a symbol indicating that the frequency band is to be
attenuated.
[0038]
The display unit 6 displays how the audio signal is amplified, and displays the result of the
spectrum analysis by the equalizer unit 3 as a bar graph and a curve. The control microcomputer
7 is realized by a microcomputer and controls the sound quality adjustment device 1 in an
integrated manner. The coefficient storage unit 8 is realized by, for example, a volatile memory
and a non-volatile memory, and stores an increase rate and a decrease rate in a plurality of
frequency bands.
[0039]
FIG. 3 is an explanatory view for explaining an audio adjustment mode by the sound quality
adjustment device 1. The vertical axis of FIG. 3 represents the variation of the sound pressure
level by the sound quality adjustment device 1, and the horizontal axis represents the frequency.
First, when the operator presses the frequency switching buttons 5c and 5d of the operation
input unit 5 to select a desired center frequency, the selected center frequency is given to the
control microcomputer 7. Here, the case where 1 kHz is selected as the center frequency and the
standard frequency band is the selected frequency band will be described. Next, when the
operator presses the UP button 5a of the operation input unit 5 and inputs +1 step, the control
microcomputer 7 is given an instruction to increase the sound pressure level of the selected
frequency band by 1 step. Based on this command, the control microcomputer 7 instructs the
equalizer unit 3 to increase the sound pressure level of the selected frequency band by an
increase amount obtained based on a predetermined increase rate, for example, a command to
amplify the selected frequency band by +1 dB. give. Here, the increase rate is 1 dB / 1 step.
[0040]
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The equalizer unit 3 amplifies the sound pressure level of the selected frequency band in the
audio signal from the input selection unit 2 by the calculated increment, that is, +1 dB here, and
amplifies it. Give to. For example, to amplify the high frequency band by +1 dB, as shown in FIG.
3, the increase in sound pressure level gradually increases from the lowest frequency of the
selected frequency band toward the center frequency, and the sound pressure level at the center
frequency increases. The sound pressure level in the selected frequency band is increased
according to a change curve a1 in which the amount is the maximum value and is 1 dB and the
increase in sound pressure level gradually decreases from the center frequency toward the
highest frequency. Say. Therefore, when the operator presses the UP button 5a of the operation
input unit 5 to increase the amount of increase by one step, the amount of amplification of the
selected frequency band increases by +1 dB. When +2 dB amplification is performed, the sound
pressure level is changed according to change curve a2. When +3 dB amplification is performed,
the sound pressure level is changed according to change curve a3. When -1 dB amplification is
performed, the sound pressure level according to change curve b1 Is changed, and the sound
pressure level is changed according to the change curve b2 when amplifying -2 dB, and the
sound pressure level is changed according to the change curve b3 when amplifying -3 dB.
[0041]
On the other hand, when the operator presses the DOWN button 5b of the operation input unit 5
to input -1 step, the control microcomputer 7 is given a command to attenuate the sound
pressure level of the selected frequency band by 1 step. Based on this command, the control
microcomputer 7 reduces the sound pressure level of the selected frequency band by a reduction
amount obtained based on a predetermined reduction rate, for example, an equalizer unit that
attenuates the selected frequency band by -2 dB. Give to three. Here, the reduction rate is 2 dB /
1 step.
[0042]
The equalizer unit 3 attenuates the sound pressure level of the selected frequency band in the
audio signal from the input selection unit 2 by the calculated reduction amount based on the
command from the control microcomputer 7, that is, amplifies here by -2 dB, Give to four. With 2 dB amplification, as shown in FIG. 3, the decrease in sound pressure level gradually increases
from the lowest frequency of the selected frequency band toward the center frequency, and the
decrease in sound pressure level at the center frequency is the maximum value That is, the sound
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pressure level in the selected frequency band is decreased according to a change curve in which
the decrease in sound pressure level gradually decreases from the center frequency toward the
highest frequency by 2 dB. Therefore, when the operator presses the DOWN button 5b of the
operation input unit 5 to increase the decrease amount by one step, the amplification amount of
the selected frequency band increases by -2 dB.
[0043]
When 250 Hz is selected as the center frequency, 4 kHz is selected as the center frequency when
the low frequency band is the selected frequency band, and when the high frequency band is the
selected frequency band, the standard frequency band is the selected frequency. Since the same
control as in the case of the band is performed, the description is omitted.
[0044]
As described above, in the present embodiment, when the selected frequency band is amplified in
accordance with the amount of increase or the amount of attenuation input by the operator, the
control microcomputer 7 determines an attenuation rate for determining the amount of
reduction in sound pressure level from the amount of attenuation. It is set to a value larger than
the rate of increase for obtaining the amount of increase in sound pressure level from the
amount of increase.
Therefore, the reduction amount of the sound pressure level when the selected frequency band is
attenuated by one step is larger than the increase amount of the sound pressure level when the
selected frequency band is increased by one step. Specifically, when the UP button 5a is pressed
and the amount of increase increases from 0 to 1 step, the amount of amplification increases by
1 dB, and when the DOWN button 5 b is pressed and the amount of attenuation increases from 0
to 1 step The amount of amplification increases by -2 dB. In other words, when the control
microcomputer 7 amplifies the selected frequency band in accordance with the amount of
increase or the amount of attenuation input by the operator, the control microcomputer 7
determines the attenuation rate for determining the amount of decrease in sound pressure
energy from the amount of attenuation The value is set to a value larger than the rate of increase
for obtaining the amount of increase in pressure energy. This is because changing the sound
pressure level of the audio signal changes the sound pressure energy of the audio signal.
Therefore, the control microcomputer 7 controls the equalizer unit 3 so that the reduction
amount of sound pressure energy when the selected frequency band is attenuated by one step is
larger than the increase amount of the sound pressure energy when the selected frequency band
is increased by one step. doing.
08-05-2019
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[0045]
Here, the change amount (increase amount or decrease amount) of the sound pressure energy is
the area of a portion surrounded by the change curve of the sound pressure level and the
horizontal axis shown in FIG. As can be seen from FIG. 3, when amplifying the selected frequency
band in the audio signal, the area surrounded by the change curve and the horizontal axis when
the selected frequency band is attenuated by one step enhances the selected frequency band by
one step. It can be seen that the area surrounded by the change curve of and the horizontal axis
is larger. This relationship holds true for the case of the two-step attenuation and the two-step
enhancement as well as the case of the three-step attenuation and the three-step enhancement.
[0046]
According to the first embodiment, the following effects can be obtained. (1) According to the
first embodiment, the operator presses the DOWN button 5b more than the increase amount of
the sound pressure energy when the operator presses the UP button 5a to increase the
intensification amount from 0 to 1 step. The amount of decrease in sound pressure energy when
the amount of attenuation is increased from 0 to 1 step is larger. Therefore, the operator can
sense the rising degree of the sound pressure level when the selected frequency band is
increased by one step and the decreasing degree of the sound pressure level when attenuated by
one step to the same extent. By this, it is possible to perform the sound quality adjustment in
which the sound quality adjustment content inputted by the operator and the sound quality
change (psycho-acoustic sense) of the actual sound signal felt by the operator are matched.
Therefore, even an operator who is unfamiliar with the operation can easily perform sound
quality adjustment adapted to human hearing.
[0047]
The first embodiment may be modified as follows. In the above embodiment, the increase rate of
the sound pressure level at the time of enhancement is 1 dB / step, and the decrease rate of the
sound pressure level at the attenuation is 2 dB / step. The reduction rate may be larger than the
increase rate of the sound pressure level at the time of enhancement.
08-05-2019
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[0048]
In the above embodiment, although three frequency bands to be subjected to sound quality
adjustment are set, four or more frequency bands may be set, or two frequency bands may be
set. Further, only one frequency band to be subjected to the sound quality adjustment may be set.
[0049]
Second Embodiment Next, a second embodiment of the present invention will be described with
reference to FIG. The second embodiment has a configuration in which the sound quality
adjustment mode of the first embodiment is changed, and therefore the detailed description of
the same parts will be omitted. FIG. 4 is an explanatory view showing an audio adjustment mode
according to the second embodiment. The vertical axis in FIG. 4 represents the variation of the
sound pressure level by the sound quality adjustment device 1, and the horizontal axis represents
the frequency.
[0050]
In the second embodiment, regarding the increase rate of the sound pressure level, the increase
rate in the low frequency band and the increase rate in the high frequency band are set to values
larger than the increase rate in the standard frequency band, and the sound pressure level
decreases. For the rate, the reduction rate in the low frequency band and the reduction rate in
the high frequency band are set to values larger than the reduction rates in the standard
frequency band. Furthermore, for the rate of increase and the rate of decrease in each frequency
band, the rate of decrease is set to a value larger than the rate of increase.
[0051]
(1) In the case of amplifying the standard frequency band First, when the operator presses the
frequency switching buttons 5c and 5d of the operation input unit 5 to select 1 kilohertz as the
center frequency, 1 kilohertz is selected as the center frequency. A command is given to the
control microcomputer 7. Next, when the operator presses the UP button 5a of the operation
input unit 5 to input +1 step, the control microcomputer 7 is instructed to increase the sound
08-05-2019
18
pressure level in the standard frequency band by 1 step. Based on this command, the control
microcomputer 7 instructs the equalizer unit 3 to increase the sound pressure level of the
standard frequency band by an increase amount obtained based on a predetermined increase
rate, for example, a command to amplify the standard frequency band by +1 dB. give. Here, the
increase rate is 1 dB / 1 step.
[0052]
The equalizer unit 3 boosts the sound pressure level in the standard frequency band of the audio
signal from the input selection unit 2 by the calculated increment based on the command from
the control microcomputer 7, that is, amplifies it by +1 dB here to obtain the amplifier 4. Give to.
Therefore, when the operator presses the UP button 5a of the operation input unit 5 to increase
the amount of increase by one step, the amount of amplification of the standard frequency band
in the audio signal from the input selection unit 2 increases by +1 dB.
[0053]
On the other hand, when the operator presses the DOWN button 5b of the operation input unit 5
to input -1 step, the control microcomputer 7 is given a command to attenuate the sound
pressure level in the standard frequency band by 1 step. Based on this command, the control
microcomputer 7 reduces the sound pressure level in the standard frequency band by a
reduction amount determined in advance based on the reduction rate, for example, a command
to amplify the standard frequency band by -2 dB. Give to. Here, the reduction rate is 2 dB / 1
step.
[0054]
The equalizer unit 3 attenuates the sound pressure level in the standard frequency band of the
audio signal from the input selection unit 2 by the calculated reduction amount based on the
command from the control microcomputer 7, that is, amplifies here by-2 dB and Give to four.
Therefore, when the operator presses the DOWN button 5b of the operation input unit 5 to
increase the attenuation amount by one step, the amplification amount of the standard frequency
band in the audio signal from the input selection unit 2 increases by -2 dB.
08-05-2019
19
[0055]
(2) In the case of amplifying the low frequency band First, when the operator presses the
frequency switching buttons 5c and 5d of the operation input unit 5 to select 250 Hz as the
center frequency, 250 Hz is selected as the center frequency. A command is given to the control
microcomputer 7. Next, when the operator presses the UP button 5a of the operation input unit 5
to input +1 step, the control microcomputer 7 is given an instruction to increase the sound
pressure level in the low frequency band by 1 step. Based on this command, the control
microcomputer 7 instructs the equalizer unit 3 to increase the sound pressure level in the low
frequency band by an increase amount obtained on the basis of a predetermined increase rate,
for example, a command to amplify the low frequency band by +2 dB. give. Here, the increase
rate is 2 dB / 1 step.
[0056]
The equalizer unit 3 amplifies the sound pressure level in the low frequency band of the audio
signal from the input selection unit 2 by the calculated increment based on the command from
the control microcomputer 7, that is, here amplifies it by +2 dB, Give to. Therefore, when the
operator presses the UP button 5a of the operation input unit 5 to increase the amount of
increase by one step, the amount of amplification in the low frequency band of the audio signal
from the input selection unit 2 increases by +2 dB.
[0057]
On the other hand, when the operator presses the DOWN button 5b of the operation input unit 5
to input -1 step, the control microcomputer 7 is given a command to attenuate the sound
pressure level in the low frequency band by 1 step. Based on this command, the control
microcomputer 7 reduces the sound pressure level in the low frequency band by a reduction
amount determined based on a predetermined reduction rate, for example, a command to amplify
the low frequency band by -3 dB by the equalizer unit 3 Give to. Here, the reduction rate is 3 dB /
1 step.
[0058]
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20
The equalizer unit 3 attenuates the sound pressure level in the low frequency band of the audio
signal from the input selection unit 2 by the calculated reduction amount based on the command
from the control microcomputer 7, that is, amplifies it by -3 dB in this case, Give to four.
Therefore, when the operator presses the DOWN button 5b of the operation input unit 5 to
increase the attenuation amount by one step, the amplification amount of the low frequency
band in the audio signal from the input selection unit 2 increases by -3 dB.
[0059]
(3) When amplifying the high frequency band When increasing the high frequency band, except
that the operator presses the frequency switching buttons 5c and 5d of the operation input unit
5 to select 4 kHz as the center frequency, Since the same control as in the case of amplifying the
low frequency band is performed, the description will be omitted.
[0060]
The relationship between the amount of enhancement and the amount of attenuation and the
amount of amplification in each frequency band is as shown in Table 1 below.
[0061]
As described above, in the present embodiment, the control microcomputer 7 calculates the
increase rate of the low frequency band and the increase rate of the high frequency band for the
increase rate for obtaining the increase amount of the sound pressure level based on the increase
amount input by the operator. And are set to values larger than the increase rate of the standard
frequency band.
Further, the control microcomputer 7 determines the reduction rate of the low frequency band
and the reduction rate of the high frequency band as the reduction rate for determining the
reduction amount of the sound pressure level based on the attenuation amount input by the
operator. It is set to a value larger than the decrease rate of
[0062]
Specifically, when the standard frequency band is selected, when the UP button 5a is pressed and
the amount of increase increases from 0 to 1 step, the amount of amplification increases by +1
08-05-2019
21
dB and the DOWN button 5b is pressed When the amount of attenuation increases from 0 to 1
step, the amount of amplification increases by -2 dB.
On the other hand, when the low frequency band or the high frequency band is selected, when
the UP button 5a is pressed and the amount of increase is increased by +1 step, the amount of
amplification is increased by +2 dB and the DOWN button 5b is pressed. When the amount of
attenuation increases from 0 to 1 step, the amount of amplification increases by -3 dB.
[0063]
In other words, in the control microcomputer 7, the increase amount of sound pressure energy
when the low frequency band and the high frequency band are increased by one step is larger
than the increase amount of sound pressure energy when the standard frequency band is
increased by one step. Control the equalizer unit 3. In addition, the control microcomputer 7 is
an equalizer so that the reduction amount of sound pressure energy when the low frequency
band and the high frequency band are attenuated by one step is larger than the reduction
amount of sound pressure energy when the standard frequency band is attenuated by one step.
Control part 3.
[0064]
Here, the change amount (increase or decrease amount) of the sound pressure energy is the area
of a portion surrounded by the change curve of the sound pressure level and the horizontal axis
shown in FIG. As can be seen from FIG. 4, the area surrounded by the change curves a11 and a12
when the low frequency band and the high frequency band are enhanced by one step and the
horizontal axis is the change curve a13 when the standard frequency band is enhanced by one
step and It can be seen that the area enclosed by the horizontal axis is larger. This relationship
also holds true for the two-step enhancement and the three-step enhancement. Furthermore,
when attenuated, the area surrounded by the change curves in the low frequency band and the
high frequency band and the horizontal axis is larger than the area surrounded by the change
curves in the standard frequency band and the horizontal axis.
[0065]
08-05-2019
22
Furthermore, in the present embodiment, as in the first embodiment, the control microcomputer
7 decreases the sound pressure level reduction amount from the attenuation amount when
amplifying the selected frequency band according to the increase amount or the attenuation
amount input by the operator. The attenuation rate to be determined is set to a value larger than
the increase rate to determine the increase amount of the sound pressure level from the
enhancement amount. Therefore, the amount of decrease in sound pressure level when the
selected frequency band is attenuated by one step is larger than the amount of increase in sound
pressure level when the selected frequency band is increased by one step.
[0066]
Thus, in the second embodiment, the low frequency band and the high frequency band are
enhanced more than the increase in sound pressure energy when the operator increases the
amount of increase by 0 to 1 step to enhance the standard frequency band. Therefore, the
amount of increase in sound pressure energy when the amount of increase is increased from 0 to
1 step is larger. In addition, the attenuation amount is 0 to attenuate the low frequency band and
the high frequency band more than the decrease amount of the sound pressure energy when the
operator increases the attenuation amount from 0 to 1 step to attenuate the standard frequency
band. The amount of decrease in sound pressure energy when it is increased by one step from.
[0067]
Therefore, the operator feels the rising degree of the sound pressure level when the standard
frequency band is increased by one step and the rising degree of the sound pressure level when
the low frequency band and the high frequency band are increased by one step. be able to.
Similarly, the operator has the same degree of decrease in sound pressure level when the
standard frequency band is attenuated by one step and the degree of decrease in sound pressure
level when the low frequency band and the high frequency band are attenuated by one step. I can
feel it.
[0068]
As in the first embodiment, in each frequency band, the operator DOWN more than the increase
amount of the sound pressure energy when the operator presses the UP button 5a to increase
the intensification amount from 0 to 1 step at a time. When the button 5b is pressed to increase
08-05-2019
23
the attenuation amount from 0 to 1 step, the reduction amount of the sound pressure energy is
larger. Therefore, the operator can sense the rising degree of the sound pressure level when the
selected frequency band is increased by one step and the decreasing degree of the sound
pressure level when attenuated by one step to the same extent.
[0069]
As described above, also in the second embodiment, the same effect as that of the first
embodiment can be obtained. The second embodiment may be modified as follows.
[0070]
In the above embodiment, when the standard frequency band is selected, the sound pressure
level increase rate is 1 dB / 1 step, and the sound pressure level decrease rate is 2 dB / 1 step,
but the sound pressure level decrease The rate should be greater than the rate of increase of the
sound pressure level. Similarly, when the low frequency band and the high frequency band are
selected, the sound pressure level increase rate is 2 dB / 1 step, and the sound pressure level
decrease rate is 3 dB / 1 step. The reduction rate may be larger than the increase rate of the
sound pressure level.
[0071]
In the above embodiment, although three frequency bands to be subjected to sound quality
adjustment are set, four or more frequency bands may be set, or two frequency bands may be
set. Further, only one frequency band to be subjected to the sound quality adjustment may be set.
[0072]
・ When setting 2 or more of low frequency band and high frequency band, increase rate of
sound pressure level is set to increase as frequency band goes away from standard frequency
band, and decrease rate of sound pressure level It may be set to be a larger value as it goes away
from the standard frequency band. This enables more effective sound quality adjustment. For
08-05-2019
24
example, in a standard frequency band with a center frequency of 1 kilohertz, the increase rate
during enhancement is 1 dB / 1 step, the decrease rate during attenuation is 2 dB / 1 step, and
the low frequency bands with a center frequency of 250 Hz and 500 Hz For high frequency
bands with center frequencies of 2 kHz and 4 kHz, increase rate at enhancement is +1.5 dB / 1
step, decrease rate at decay is 2.5 dB / step, center frequency is 63 Hz and 125 Hz In the ultra
low frequency band of and the ultra high frequency bands of 8 kHz and 16 kHz center frequency,
the increase rate at the time of enhancement may be 2 dB / 1 step, and the decrease rate at the
attenuation may be 3 dB / 1st ep.
[0073]
Third Embodiment Next, a third embodiment of the present invention will be described. The third
embodiment is a configuration in which the sound quality adjustment mode of the first
embodiment is changed, and therefore the detailed description of the same parts will be omitted.
[0074]
In the third embodiment, the increase rate and the decrease rate of the sound pressure level are
set to increase as the number of steps (increase amount or attenuation amount) from 0, which is
the reference value, increases. Furthermore, for the increase rate and the decrease rate of the
sound pressure level, the decrease rate is set to a value larger than the increase rate. Table 2
below shows an example of the relationship between the amount of enhancement and the
amount of attenuation and the amount of amplification in the standard frequency band.
[0075]
In the sound quality adjustment mode shown in Table 2, when +1 step is input, +1 dB
amplification is performed, +2 step input is +3 dB amplification, and +3 dB is +6 dB amplification.
When -1 step is input, -2 dB amplification is performed, -2 step is input, -6 dB amplification is
performed, and -3 step is input, -12 dB amplification is performed.
[0076]
08-05-2019
25
Also in the low frequency band and the high frequency band, the same relationship as the
standard frequency band is established. As described above, also in the third embodiment, the
same effect as that of the first embodiment can be obtained.
[0077]
Fourth Embodiment Next, a fourth embodiment of the present invention will be described with
reference to FIGS. 5 and 6. The fourth embodiment is a configuration in which the sound quality
adjustment mode of the first embodiment is changed, and therefore the detailed description of
the same parts will be omitted.
[0078]
In the fourth embodiment, the reduction rate of the sound pressure level is set to a value larger
than the increase rate of the sound pressure level. That is, the reduction rate of the sound
pressure level when the DOWN button 5b is pushed once to attenuate by 1 step is set to a value
larger than the increase rate of the sound pressure level when the UP button 5a is pushed once
to increase by 1 step.
[0079]
FIG. 5 is a flowchart for explaining the processing procedure at the time of sound quality
adjustment, and FIG. 6 is a timing chart showing the processing procedure at the time of sound
quality adjustment. At step n1, the control microcomputer 7 determines whether the UP button
5a is pressed. If it is determined that the UP button 5a is pressed, the process proceeds to step
n2. At step n2, the control microcomputer 7 gives the equalizer unit 3 a command to increase the
amplification amount by 1 dB. That is, as shown in FIG. 6, at the timings t1, t2, t3, t7 and t8 when
the UP button 5a is pressed, the amplification amount of the equalizer section 3 is increased by 1
dB each. Thereafter, the process proceeds to step n3.
[0080]
On the other hand, if it is determined in step n2 that the UP button 5a is not pressed, the process
08-05-2019
26
proceeds to step n4. At step n4, the control microcomputer 7 determines whether the DOWN
button 5b is pressed. If it is determined that the DOWN button 5b is pressed, the process
proceeds to step n5. If it is determined that the DOWN button 5b is not pressed, the process
returns to step n1. At step n5, the control microcomputer 7 gives the equalizer unit 3 a command
to reduce the amplification amount by 2 dB. That is, as shown in FIG. 6, at the timings t4, t5, t6,
and t9 when the DOWN button 5b is pressed, the amplification amount of the equalizer unit 3 is
decreased by 2 dB each. Thereafter, the process proceeds to step n3.
[0081]
At step n3, the control microcomputer 7 determines whether or not the sound quality adjustment
has been completed. Whether or not the sound quality adjustment has ended is determined
based on the input content from the operation input unit 5. If it is determined that the sound
quality adjustment has not ended, the process returns to step n1. If it is determined that the
sound quality adjustment has ended, the process ends. As described above, also in the fourth
embodiment, the same effect as that of the first embodiment can be obtained.
[0082]
Fifth Embodiment Next, a fifth embodiment of the present invention will be described with
reference to FIG. The fifth embodiment is a configuration in which the sound quality adjustment
mode of the first embodiment is changed, and therefore the detailed description of the same
parts will be omitted.
[0083]
In the fifth embodiment, the decrease rate of the sound pressure level is set to a value larger than
the increase rate of the sound pressure level, and the increase rate and the decrease rate are
changed according to the current amplification amount set at the time of adjustment operation. I
am trying to do it. That is, the reduction rate of the sound pressure level when the DOWN button
5b is pushed once to attenuate by 1 step is set to a value larger than the increase rate of the
sound pressure level when the UP button 5a is pushed once to increase by 1 step. The rate and
the rate of increase are respectively changed according to the current amplification amount.
08-05-2019
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[0084]
FIG. 7 is a flowchart for explaining the processing procedure at the time of sound quality
adjustment. At step m1, the control microcomputer 7 determines whether the UP button 5a is
pressed. If it is determined that the UP button 5a is pressed, the process proceeds to step m2. In
step m 2, the control microcomputer 7 determines an increase amount in accordance with the
amplification amount currently set in the equalizer unit 3. For example, the amount of increase is
determined according to Table 3 below. Table 3 is stored in advance in the coefficient storage
unit 8.
[0085]
At step m3, the control microcomputer 7 gives the equalizer unit 3 a command to set the
amplification amount determined at step m2. Thereafter, the process proceeds to step m4.
[0086]
On the other hand, when it is determined in step m2 that the UP button 5a is not pressed, the
process proceeds to step m5. At step m5, the control microcomputer 7 determines whether the
DOWN button 5b is pressed. If it is determined that the DOWN button 5b is pressed, the process
proceeds to step m6. If it is determined that the DOWN button 5b is not pressed, the process
returns to step m1. In step m6, the control microcomputer 7 determines the amount of decrease
according to the amount of amplification currently set in the equalizer unit 3. For example, the
amount of reduction is determined according to Table 4 below. Table 4 is stored in advance in
the coefficient storage unit 8.
[0087]
At step m7, the control microcomputer 7 gives the equalizer unit 3 a command to set the amount
of decrease determined at step m6. Thereafter, the process proceeds to step m4.
[0088]
08-05-2019
28
At step m4, the control microcomputer 7 determines whether or not the sound quality
adjustment has been completed. Whether or not the sound quality adjustment has ended is
determined based on the input content from the operation input unit 5. If it is determined that
the sound quality adjustment has not ended, the process returns to step m1. If it is determined
that the sound quality adjustment has ended, the process ends. As described above, also in the
fifth embodiment, the same effect as that of the first embodiment can be obtained.
[0089]
Sixth Embodiment Next, a sixth embodiment of the present invention will be described with
reference to FIGS. 8 and 9. The sixth embodiment has a configuration in which the sound quality
adjustment mode of the first embodiment is changed, and therefore detailed description of the
same parts will be omitted. FIG. 8 is an explanatory view showing an audio adjustment mode
according to the sixth embodiment. The vertical axis of FIG. 8 represents the variation of the
sound pressure level by the sound quality adjustment device 1, and the horizontal axis represents
the frequency.
[0090]
In the sixth embodiment, the Q value for attenuation when a voice signal is attenuated is set to a
value smaller than the Q value for enhancement when a voice signal is enhanced for the Q value
described later. FIG. 9 is an explanatory diagram for explaining the relationship between the Q
value and the sound pressure energy. Curves L1 and L2 shown in FIG. 9 indicate the amount of
change (the amount of increase in FIG. 9) of the sound pressure level for each frequency at the
time of sound quality adjustment. The change patterns of change curves L1 and L2 are almost
the same, and the sound pressure level gradually increases from the lowest frequency toward the
center frequency, the sound pressure level at the center frequency reaches the maximum, and
the center frequency goes from the center frequency to the highest frequency Is a change
pattern in which the sound pressure level gradually decreases.
[0091]
The Q value is a numerical value indicating the sharpness of the amplitude response in the audio
signal, and the larger the Q value, the sharper the change curve of the sound pressure level. Q1,
08-05-2019
29
which is the Q value of the change curve L1, is expressed by the following equation (1). Q1 = fc /
(fH1-fL1) (1) In the equation (1), fc is the central frequency of the frequency band indicated by
the change curve L1, fL1 is the lowest frequency of the frequency band indicated by the change
curve L1, and fH1 is the change curve This is the highest frequency in the frequency band
indicated by L1. Further, Q2 which is a Q value of the change curve L2 is expressed by the
following equation (2).
[0092]
Q2 = fc / (fH2-fL2) (2) In the equation (2), fc is the central frequency of the frequency band
indicated by the change curve L2, fL2 is the lowest frequency of the frequency band indicated by
the change curve L2, and fH2 is the change curve This is the highest frequency in the frequency
band indicated by L2. As shown in FIG. 9, since the change curve L2 is sharper than the change
curve L1, it is understood that Q2 takes a larger value than Q1.
[0093]
Further, it can also be seen that the amount of change in sound pressure energy is larger in the
change curve L1 than in the change curve L2. The amount of change in sound pressure energy is
the area of the portion enclosed by the change curve of the sound pressure level shown in FIG. 9
and the horizontal axis. Therefore, when the change pattern of the sound pressure level is
substantially the same, the change amount of the sound pressure energy becomes smaller as the
Q value is larger.
[0094]
The sound quality adjustment procedure of the audio signal will be described with reference to
FIG. 8 again. First, when the operator presses the frequency switching buttons 5c and 5d of the
operation input unit 5 to select a predetermined center frequency, the selected center frequency
is given to the control microcomputer 7. Here, the case where 1 kHz is selected as the center
frequency and the standard frequency band is the selected frequency band will be described.
Next, when the operator presses the UP button 5a of the operation input unit 5 and inputs +1
step, the control microcomputer 7 is given an instruction to increase the sound pressure level of
the selected frequency band by 1 step. Based on this command, the control microcomputer 7
increases the sound pressure level of the selected frequency band by an increase amount
08-05-2019
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obtained based on a predetermined increase rate, for example, an equalizer unit 3 that amplifies
the selected frequency band by +1 dB. Give to. Here, the increase rate is 1 dB / 1 step.
[0095]
The equalizer unit 3 amplifies the sound pressure level of the selected frequency band in the
audio signal from the input selection unit 2 by the calculated increment, that is, +1 dB here, and
amplifies it. Give to. With +1 dB amplification, as shown in FIG. 8, the increase in sound pressure
level gradually increases from the lowest frequency of the selected frequency band toward the
center frequency, and the increase in sound pressure level at the center frequency is at the
maximum value To increase the sound pressure level in the selected frequency band according to
the change curves a21, a22 and a23 which are 1 dB and increase in the sound pressure level
gradually decreases from the center frequency toward the highest frequency. . Therefore, when
the operator presses the UP button 5a of the operation input unit 5 to increase the amount of
increase by one step, the amount of amplification of the selected frequency band in the audio
signal from the input selection unit 2 increases by +1 dB.
[0096]
On the other hand, the operator presses the DOWN button 5b of the operation input unit 5 to
input -1 step. The control microcomputer 7 is given a command for attenuating the sound
pressure level of the selected frequency band by 1 step. Based on this command, the control
microcomputer 7 reduces the sound pressure level of the selected frequency band by a reduction
amount determined based on a predetermined reduction rate, for example, a command to amplify
the selected frequency band by −1 dB. Give to. Here, the reduction rate is 1 dB / 1 step.
[0097]
The equalizer unit 3 attenuates the sound pressure level of the selected frequency band in the
audio signal from the input selection unit 2 by the calculated reduction amount based on the
command from the control microcomputer 7, that is, amplifies here by −1 dB. Give to four. With
-1 dB amplification, as shown in FIG. 8, the decrease amount of the sound pressure level
gradually increases from the lowest frequency of the selected frequency band toward the center
frequency, and the decrease amount of the sound pressure level of the center frequency is the
maximum value To reduce the sound pressure level in the selected frequency band according to
08-05-2019
31
the change curves b21, b22 and b23 such that the decrease in sound pressure level gradually
decreases from the center frequency toward the highest frequency. Say. Therefore, when the
operator presses the DOWN button 5b of the operation input unit 5 to increase the decrease
amount by one step, the amplification amount of the selected frequency band in the audio signal
from the input selection unit 2 increases by -1 dB.
[0098]
At this time, in the case of attenuating the sound pressure level in the selected frequency band,
the Q value is smaller than in the case of enhancing the sound pressure level in the selected
frequency band. For example, the Q value when the sound pressure level in the selected
frequency band is attenuated by 1 step (1 dB) is 0.8, and the Q value when the sound pressure
level in the selected frequency band is increased by 1 step (1 dB) is 1. is there.
[0099]
Therefore, when amplifying the selected frequency band in the audio signal, the control
microcomputer 7 equalizes the decrease rate of the sound pressure level at the time of
attenuation and the increase rate of the sound pressure level at the time of enhancement. The
equalizer unit 3 is controlled so that the value is smaller than the enhancement Q value.
Specifically, when the UP button 5a is pressed and the amount of increase increases from 0 to 1
step, the amount of amplification increases by +1 dB, and when the DOWN button 5 b is pressed
and the amount of attenuation increases from 0 to 1 step The amount of amplification increases
by -1 dB. At this time, the enhancement Q value is 1 and the attenuation Q value is 0.8. In other
words, when amplifying the selected frequency band in the audio signal, the control
microcomputer 7 reduces the amount of decrease in sound pressure energy when it is attenuated
by one step more than the amount of increase in sound pressure energy when it is increased by
one step. The equalizer unit 3 is controlled to be
[0100]
The standard frequency band is also selected when 250 Hz is selected as the center frequency, 4
kHz is selected as the center frequency band when the low frequency band is the selected
frequency band, and when the high frequency band is the selected frequency band. Since the
same control as in the case of the frequency band is performed, the description will be omitted.
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[0101]
As described above, in the sixth embodiment, the operator presses the DOWN button 5b more
than the increase amount of the sound pressure energy when the operator presses the UP button
5a to increase the intensification amount from 0 to 1 step. The amount of attenuation of the
sound pressure energy when the amount of attenuation is increased from 0 to 1 step is larger.
Therefore, it is possible to sense the rising degree of the sound pressure level when the selected
frequency band is increased by one step and the decreasing degree of the sound pressure level
when attenuated by one step to the same extent. As a result, it is possible to perform the sound
quality adjustment in which the sound quality adjustment content input by the operator and the
sound quality change (psycho-acoustic sense) of the actual sound signal felt by the operator
match. Therefore, even an operator who is unfamiliar with the operation can easily perform
sound quality adjustment adapted to human hearing.
[0102]
As described above, also in the sixth embodiment, the same effect as that of the first embodiment
can be obtained. The sixth embodiment may be modified as follows.
[0103]
In the above embodiment, although the enhancement Q value is 1 and the attenuation Q value is
0.8, any value may be set as long as the attenuation Q value is smaller than the enhancement Q
value. It is also good. In the above embodiment, the increase rate for obtaining the increase
amount of the sound pressure level from the increase amount input by the operator and the
decrease rate for determining the decrease amount of the sound pressure level from the
attenuation amount input by the operator are made the same value. Although set, as in the first
embodiment, the decrease rate may be set to a value larger than the increase rate. Further, as in
the second embodiment, the rate of increase in the low frequency band and the rate of increase
in the high frequency band are set to values larger than the rate of increase in the standard
frequency band, and the decrease rate in the low frequency band and the high frequency band
The reduction rate at may be set to a value larger than the reduction rate in the standard
frequency band.
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[0104]
In the above embodiment, although three frequency bands to be subjected to sound quality
adjustment are set, four or more frequency bands may be set, or two frequency bands may be
set. Further, only one frequency band to be subjected to the sound quality adjustment may be set.
[0105]
Seventh Embodiment Next, a seventh embodiment of the present invention will be described with
reference to FIG. The seventh embodiment has a configuration in which the sound quality
adjustment mode of the sixth embodiment is changed, and therefore the detailed description of
the same parts will be omitted. FIG. 10 is an explanatory view showing a sound quality
adjustment mode according to the seventh embodiment. The vertical axis in FIG. 10 represents
the variation of the sound pressure level by the sound quality adjustment device 1, and the
horizontal axis represents the frequency.
[0106]
In the seventh embodiment, with regard to the enhancement Q value, the enhancement Q value
in the low frequency band and the enhancement Q value in the high frequency band are set to
values smaller than the enhancement Q value in the standard frequency band, and attenuated.
With regard to the Q value for use, the Q value for attenuation in the low frequency band and the
Q value for attenuation in the high frequency band are set to values smaller than the
enhancement Q value in the standard frequency band. Furthermore, for the enhancement Q value
and the attenuation Q value in each frequency band, the reduction Q value is set to a value
smaller than the enhancement Q value.
[0107]
(1) In the case of amplifying the standard frequency band First, when the operator presses the
frequency switching buttons 5c and 5d of the operation input unit 5 to select 1 kilohertz as the
center frequency, 1 kilohertz is selected as the center frequency. A command is given to the
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control microcomputer 7. Next, when the operator presses the UP button 5a of the operation
input unit 5 to input +1 step, the control microcomputer 7 is instructed to increase the sound
pressure level in the standard frequency band by 1 step. Based on this command, the control
microcomputer 7 instructs the equalizer unit 3 to increase the sound pressure level of the
standard frequency band by an increase amount obtained based on a predetermined increase
rate, for example, a command to amplify the standard frequency band by +1 dB. give. Here, the
increase rate is 1 dB / 1 step.
[0108]
The equalizer unit 3 amplifies the sound pressure level in the standard frequency band by the
determined increment, that is, +1 dB in this case, and applies the amplified sound pressure level
to the amplifier 4 based on a command from the control microcomputer 7. Therefore, when the
operator presses the UP button 5a of the operation input unit 5 to increase the amount of
increase by one step, the amount of amplification of the standard frequency band increases by +1
dB.
[0109]
On the other hand, when the operator presses the DOWN button 5b of the operation input unit 5
to input -1 step, the control microcomputer 7 is given a command to attenuate the sound
pressure level in the standard frequency band by 1 step. Based on this command, the control
microcomputer 7 gives the equalizer unit 3 a command for attenuating the sound pressure level
in the standard frequency band by a reduction amount obtained based on a predetermined
reduction rate, for example, a command for amplifying -1 dB. Here, the reduction rate is 1 dB / 1
step.
[0110]
The equalizer unit 3 attenuates the sound pressure level in the standard frequency band of the
audio signal from the input selection unit 2 by the calculated reduction amount based on the
command from the control microcomputer 7, that is, amplifies it by −1 dB in this case, Give to
four. Therefore, when the operator presses the DOWN button 5b of the operation input unit 5 to
increase the attenuation amount by one step, the amplification amount of the standard frequency
band in the audio signal from the input selection unit 2 increases by -1 dB.
08-05-2019
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[0111]
At this time, the attenuation Q value at the time of attenuating the standard frequency band is set
to a smaller value than the enhancement Q value at the time of enhancing the standard
frequency band. For example, the enhancement Q-factor for enhancing the standard frequency
band is 1, and the attenuation Q-factor for damping the standard frequency band is 0.8.
[0112]
(2) In the case of amplifying the low frequency band First, when the operator presses the
frequency switching buttons 5c and 5d of the operation input unit 5 to select 250 Hz as the
center frequency, 250 Hz is selected as the center frequency. A command is given to the control
microcomputer 7. Next, when the operator presses the UP button 5a of the operation input unit 5
to input +1 step, the control microcomputer 7 is given an instruction to increase the sound
pressure level in the low frequency band by 1 step. Based on this instruction, the control
microcomputer 7 instructs the equalizer unit 3 to increase the sound pressure level in the low
frequency band by an increase amount obtained based on a predetermined increase rate, for
example, a command to amplify the low frequency band by +1 dB. give. Here, the increase rate is
1 dB / 1 step.
[0113]
The equalizer unit 3 amplifies the sound pressure level in the low frequency band by the
determined increment, that is, +1 dB in this case, and applies the amplified sound pressure level
to the amplifier 4 based on a command from the control microcomputer 7. Therefore, when the
operator presses the UP button 5a of the operation input unit 5 to increase the amount of
increase by one step, the amount of amplification in the low frequency band increases by +1 dB.
[0114]
On the other hand, when the operator presses the DOWN button 5b of the operation input unit 5
to input -1 step, the control microcomputer 7 is given a command to attenuate the sound
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pressure level in the low frequency band by 1 step. Based on this command, the control
microcomputer 7 sends to the equalizer unit 3 a command for attenuating the sound pressure
level in the low frequency band by a reduction amount obtained based on a predetermined
reduction rate, for example, a command for amplifying the low frequency band by 1 dB. give.
Here, the reduction rate is 1 dB / 1 step.
[0115]
The equalizer unit 3 attenuates the sound pressure level in the low frequency band by the
determined reduction amount, ie, here amplifies the signal by −1 dB based on the command
from the control microcomputer 7 and supplies the amplified signal to the amplifier 4. Therefore,
when the operator presses the DOWN button 5b of the operation input unit 5 to increase the
attenuation amount by one step, the amplification amount of the low frequency band increases
by −1 dB.
[0116]
At this time, the attenuation Q value at the time of attenuating the low frequency band is set to a
value smaller than the enhancement Q value at the time of enhancing the low frequency band.
For example, the enhancement Q value when enhancing the low frequency band is 0.9, and the
attenuation Q value when damping the low frequency band is 0.7.
[0117]
(3) When amplifying the high frequency band When increasing the high frequency band, except
that the operator presses the frequency switching buttons 5c and 5d of the operation input unit
5 to select 4 kHz as the center frequency, Since the same control as in the case of amplifying the
low frequency band is performed, the description is omitted.
[0118]
As described above, in the present embodiment, the control microcomputer 7 determines the
enhancement Q value when enhancing the low frequency band and the high frequency band with
respect to the enhancement Q value from the enhancement Q value when enhancing the
standard frequency band. Is also set to a small value.
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Further, the control microcomputer 7 sets the attenuation Q value when attenuating the low
frequency band and the high frequency band to a value smaller than the attenuation Q value
when attenuating the standard frequency band with respect to the attenuation Q value. ing.
[0119]
In other words, in the control microcomputer 7, the increase amount of sound pressure energy
when the low frequency band and the high frequency band are increased by one step is larger
than the increase amount of sound pressure energy when the standard frequency band is
increased by one step. Control the equalizer unit 3. In addition, the control microcomputer 7 is
an equalizer so that the reduction amount of sound pressure energy when the low frequency
band and the high frequency band are attenuated by one step is larger than the reduction
amount of sound pressure energy when the standard frequency band is attenuated by one step.
Control part 3.
[0120]
Here, the change amount (increase or decrease amount) of the sound pressure energy is the area
of a portion surrounded by the change curve of the sound pressure level and the horizontal axis
shown in FIG. As can be seen from FIG. 10, the area surrounded by the change curves a31 and
a32 when the low frequency band and the high frequency band are enhanced by one step and
the horizontal axis is the change curve a33 when the standard frequency band is enhanced by
one step and It can be seen that the area enclosed by the horizontal axis is larger. This
relationship also holds true for the two-step enhancement and the three-step enhancement.
Furthermore, when it attenuates, the area surrounded by the change curves in the low frequency
band and the high frequency band and the horizontal axis is larger than the area surrounded by
the change curves in the standard frequency band and the horizontal axis.
[0121]
Furthermore, in the present embodiment, as in the sixth embodiment, when amplifying the
selected frequency band, the control microcomputer 7 sets the attenuation Q value to a value
smaller than the enhancement Q value. Therefore, the reduction amount of sound pressure
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energy when the selected frequency band is attenuated from 0 to 1 step is larger than the
increase amount of the sound pressure energy when the selected frequency band is increased
from 0 to 1 step.
[0122]
Thus, in the seventh embodiment, the low frequency band and the high frequency band are
enhanced more than the increase in sound pressure energy when the operator increases the
amount of increase by 0 to 1 step to enhance the standard frequency band. Therefore, the
amount of increase in sound pressure energy when the amount of increase is increased from 0 to
1 step is larger. In addition, the attenuation amount is 0 to attenuate the low frequency band and
the high frequency band more than the decrease amount of the sound pressure energy when the
operator increases the attenuation amount from 0 to 1 step to attenuate the standard frequency
band. The amount of decrease in sound pressure energy when it is increased by one step from.
[0123]
Therefore, the operator feels the rising degree of the sound pressure level when the standard
frequency band is increased by one step and the rising degree of the sound pressure level when
the low frequency band and the high frequency band are increased by one step. be able to.
Similarly, the operator has the same degree of decrease in sound pressure level when the
standard frequency band is attenuated by one step and the degree of decrease in sound pressure
level when the low frequency band and the high frequency band are attenuated by one step. I can
feel it.
[0124]
In the seventh embodiment, as in the sixth embodiment, the increase in sound pressure energy
when the operator presses the UP button 5a to increase the increase amount from 0 to 1 step in
each frequency band as in the sixth embodiment. Also, the reduction amount of the sound
pressure energy when the operator presses the DOWN button 5b to increase the attenuation
amount from 0 to 1 step is larger. Therefore, in the selected frequency band, the operator can
sense the rising degree of the sound pressure level when the sound pressure level is increased by
one step and the lowering state of the sound pressure level when the sound pressure level is
decreased by one step.
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[0125]
As described above, also in the seventh embodiment, the same effect as that of the sixth
embodiment can be obtained. The seventh embodiment may be modified as follows.
[0126]
In the above embodiment, when the low frequency band and the high frequency band are
enhanced by setting the enhancement Q value to 1 to enhance the standard frequency band and
the attenuation Q value to attenuate the standard frequency band to 0.8. The Q factor for
enhancement is 0.9, and the attenuation Q factor for attenuating low and high frequency bands is
0.7, but the enhancement Q values for low and high frequency bands are standard frequency
bands If the enhancement Q value in the lower frequency band and the attenuation Q value in
the low frequency band and the high frequency band are smaller than the attenuation Q value in
the standard frequency band, what value should be set May be
[0127]
In each frequency band, as long as the attenuation Q value in the case of attenuating the
frequency band is smaller than the enhancement Q value in the case of enhancing the frequency
band, any value may be set.
In the above embodiment, the increase rate for obtaining the increase amount of the sound
pressure level from the increase amount input by the operator and the decrease rate for
determining the decrease amount of the sound pressure level from the attenuation amount input
by the operator are made the same value. Although set, as in the first embodiment, the decrease
rate may be set to a value larger than the increase rate. Also, as in the second embodiment, the
rate of increase in the low frequency band and the rate of increase in the high frequency band
are set to values larger than the rate of increase in the standard frequency band, and the rate of
decrease in the low frequency band and the high frequency The reduction rate in the band may
be set to a value larger than the reduction rate in the standard frequency band.
[0128]
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In the above embodiment, although three frequency bands to be subjected to sound quality
adjustment are set, four or more frequency bands may be set, or two frequency bands may be
set. Further, only one frequency band to be subjected to the sound quality adjustment may be set.
[0129]
-When setting two or more low frequency bands and two or more high frequency bands, the
enhancement Q value is set to become smaller as the frequency band moves away from the
standard frequency band, and the attenuation Q value is set to standard It may be set to become
smaller as it gets farther from the frequency band. This enables more effective sound quality
adjustment. For example, in a standard frequency band with a center frequency of 1 kilohertz, a
low frequency band with an enhancement Q value of 1 and an attenuation Q value of 0.8 and
center frequencies of 250 and 500 hertz and a center frequency of 2 kilohertz and In the high
frequency band of 4 kHz, the enhancement Q value is 0.9, the attenuation Q value is 0.7, and the
center frequencies are 63 Hz and 125 Hz ultra low frequency bands and the center frequency is
8 kHz and 16 kHz. In the ultra high frequency band, the enhancement Q value may be 0.8 and
the attenuation Q value may be 0.6.
[0130]
Eighth Embodiment Next, an eighth embodiment of the present invention will be described with
reference to FIG. The eighth embodiment has a configuration in which the sound quality
adjustment mode of the first embodiment is changed, and therefore detailed description of the
same parts will be omitted. FIG. 11 is an explanatory view showing a sound quality adjustment
mode according to the eighth embodiment. The vertical axis in FIG. 11 represents the variation of
the sound pressure level by the sound quality adjustment device 1, and the horizontal axis
represents the frequency.
[0131]
In the eighth embodiment, both the change rate of the sound pressure level and the Q value are
changed. For example, as shown in FIG. 11 and Table 5 below, the sound pressure level reduction
rate is set to a value larger than the sound pressure level increase rate, and the attenuation Q
08-05-2019
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value is smaller than the enhancement Q value. It is set to.
[0132]
Also in the low frequency band and the high frequency band, the same relationship as the
standard frequency band is established. As described above, also in the eighth embodiment, the
same effect as that of the first embodiment can be obtained.
[0133]
The eighth embodiment may be modified as follows. As shown in Table 6 below, the Q value may
be changed step by step.
[0134]
The above embodiments may be modified as follows.
[0135]
In the above embodiments, although the center frequency lower than 1 kilohertz is 250 hertz,
the center frequency lower than 1 kilohertz may be, for example, 63 hertz, 125 hertz, and 500
hertz.
Also, although the center frequency higher than 1 kilohertz is 4 kilohertz, the center frequency
higher than 1 kilohertz may be, for example, 2 kilohertz, 4 kilohertz, and 16 kilohertz.
[0136]
In each of the above embodiments, although the amount of increase and the amount of
attenuation are changed stepwise and input, they may be continuously changed and input. The
various numerical values in the above embodiments are stored in advance in the coefficient
storage unit 8 of the sound quality adjustment device 1. These various numerical values may be
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set to different numerical values when the reading device 10 is selected and when the tuner 11 is
selected. In addition, these various numerical values may be set to different numerical values for
each genre of the tune to be reproduced. Furthermore, when the sound quality adjustment device
1 is mounted on a vehicle, these various values may be set to different values depending on the
traveling state of the vehicle.
[0137]
BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the structure of the
sound quality adjustment apparatus 1 which is 1st Embodiment of this invention. FIG. 2 is a plan
view showing the appearance of the sound quality adjustment device 1; Explanatory drawing
which shows the sound quality adjustment aspect by the sound quality adjustment apparatus 1.
FIG. Explanatory drawing which shows the audio | voice adjustment aspect in 2nd Embodiment.
A flow chart for explaining a processing procedure at the time of sound quality adjustment in a
4th embodiment. The timing chart for demonstrating the process sequence at the time of sound
quality adjustment in 4th Embodiment. The flowchart for demonstrating the process sequence at
the time of sound quality adjustment in 5th Embodiment. Explanatory drawing which shows the
audio | voice adjustment aspect in 6th Embodiment. Explanatory drawing for demonstrating the
relationship between Q value and sound pressure energy. Explanatory drawing which shows the
audio | voice adjustment aspect in 7th Embodiment. Explanatory drawing which shows the sound
quality adjustment aspect in 8th Embodiment.
Explanation of sign
[0138]
DESCRIPTION OF SYMBOLS 1 ... Sound quality adjustment apparatus, 2 ... Input selection part, 3
... Equalizer part, 4 ... Amplifier, 5 ... Operation input part, 7 ... Control microcomputer.
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