close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP2012129741

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2012129741
[PROBLEMS] To automatically correct to an easy-to-hear volume by suppressing intonation of an
audio signal. SOLUTION: A setting unit 12 sets a gain according to a short time average value PS
selected by a selection unit 13 while a signal level of an input signal is rising, and a selection unit
13 selects a signal while a signal level falls. The setting unit 12 sets the gain according to the
long time average value PL. Therefore, the fluctuation range of the gain can be reduced to reduce
the intonation of the acoustic signal and the peak of the sound volume can be within the
appropriate range. [Selected figure] Figure 1
Automatic volume correction device
[0001]
The present invention relates to an automatic volume correction device suitable for a telephone
set such as an intercom apparatus.
[0002]
In a communication device for making a call via a public line, it is necessary to take into account
fluctuations in volume level due to the following factors (1) to (5).
[0003]
(1) Transmission loss difference due to difference in communication mode such as wired and
wireless, or analog communication and digital communication (2) Influence of volume difference
due to communication carrier (3) Manufacturer of telephone equipment, model of telephone
equipment such as kind (4) Influence by call mode (handset, headset, hands-free etc.) (5)
11-04-2019
1
Influence by volume adjustment function of call device The variation of the sound of the sound
from the speaker of the call device is suppressed and within a predetermined range When it is
going to store, the means to absorb / ease the volume level fluctuation | variation by the factor of
said (1)-(5) automatically is needed.
[0004]
Therefore, conventionally, an automatic volume correction device (automatic gain control device)
as described in Patent Document 1 has been mounted on a telephone apparatus.
In the conventional example described in Patent Document 1, the level fluctuation of the input
signal is obtained by regarding the long time average value of the input signal as the level of
ambient noise and performing automatic gain control while selecting the gain function according
to the ambient noise level. The output signal level is kept constant even if it is large.
[0005]
Patent No. 4321049
[0006]
However, in the above-described conventional example, there is a problem that the audio signal
is squeezed and output due to the influence of the transition of the gain function or the change of
the gain, and some unnaturalness remains in the audio ringed from the speaker. The
In addition, since a gain function with a smaller gain is selected as the ambient noise level is
larger, when ambient noise and voice are mixed, it becomes difficult to hear the volume of the
output voice when it is input with a small voice. There was also a problem of that.
[0007]
The present invention has been made in view of the above problems, and has an object of
suppressing correction of an audio signal and automatically correcting the volume to an easy-tohear volume.
11-04-2019
2
[0008]
The automatic volume correction device according to the present invention comprises a signal
output unit that adjusts and outputs a signal level of an acoustic signal, and a time average value
calculation unit that calculates a short time average value and a long time average value of the
signal level of the sound signal. A setting unit configured to set an adjustment amount of the
signal output unit according to the short time average value or the long time average value, and
the setting unit is configured to set the short time average value while the signal level of the
acoustic signal is rising. The adjustment amount is set in accordance with the above, and the
adjustment amount is set in accordance with the long time average value while the signal level of
the acoustic signal is falling.
[0009]
In this automatic volume correction device, the time average value calculation unit calculates the
short time average value such that the slope of the change of the short time average value
substantially matches the slope of the envelope at the time of rising of the sound signal
waveform. It is preferable to set the time width when doing.
[0010]
In this automatic volume correction device, the time average value calculation unit calculates the
long time average value so that the slope of the change of the long time average value
substantially matches the slope of the envelope when the sound signal waveform falls. It is
preferable to set the time width when doing.
[0011]
In this automatic volume correction device, it is preferable that the setting unit changes the
conditions for changing the setting of the adjustment amount when the signal level rises and
falls.
[0012]
In this automatic volume correction device, it is preferable that the setting unit gently change the
adjustment amount when changing the adjustment amount in the direction of increasing the
signal level.
[0013]
In this automatic volume correction device, it is preferable that the setting unit rapidly change
11-04-2019
3
the adjustment amount when changing the adjustment amount in a direction to decrease the
signal level.
[0014]
The automatic volume correction device further includes a noise detection unit that detects a
degree of noise other than voice included in the input signal, and the signal output unit detects
that the degree of noise detected by the noise detection unit is a predetermined level. When
exceeding, it is preferable to output without adjusting the signal level.
[0015]
The automatic volume correction device includes a noise suppression unit that suppresses noise
other than voice contained in the input signal, and the noise suppression unit is configured such
that the degree of noise detected by the noise detection unit exceeds a predetermined level. It is
preferable to suppress noise when it is on.
[0016]
The automatic volume correction device of the present invention has an effect that it is possible
to automatically correct the volume to an easy to hear by suppressing the intonation of the audio
signal.
[0017]
It is a block diagram showing an embodiment of an automatic volume amendment device
concerning the present invention, and an important section of an outside line transfer device.
It is a system block diagram of the intercom system for collective housing including the outside
line transfer apparatus of the same as the above.
It is explanatory drawing for demonstrating the operation | movement of the setting part in the
same as the above.
(a) is a waveform diagram of an acoustic signal, (b) is a waveform diagram showing an envelope
of the short time average value PS when the acoustic signal is an input signal and an envelope of
11-04-2019
4
a time average value output from the selection unit .
It is explanatory drawing for demonstrating the operation | movement of the setting part in the
same as the above.
It is explanatory drawing for demonstrating the operation | movement of the setting part in the
same as the above.
It is explanatory drawing for demonstrating the operation | movement of the setting part in the
same as the above.
FIG. 7 is a block diagram illustrating another embodiment of an automatic volume correction
device.
[0018]
FIG. 2 shows an example of the system configuration of an intercom system for collective
housing including an outside line transfer device E equipped with the automatic volume
correction device 1 of the present embodiment.
The intercom system for collective housing includes a plurality (only one shown) of dwelling unit
communication devices A installed in each dwelling unit of the collective housing, a lobby
intercom (not shown) installed at a common entrance of the collective housing, and a trunk line
The control unit B, the control room call unit C, the outside line transfer unit E, and the like are
included.
[0019]
Each dwelling unit communication device A is branch-connected to the main line L1 via the
dwelling unit line L2 and the branching unit D.
11-04-2019
5
The trunk line L1 is connected to the trunk line control device B, and a plurality of (only one
shown) branching devices D are provided on the trunk line L1.
In addition, a control room call apparatus C is connected to the trunk control apparatus B via a
signal line L3.
The control room communication device C is installed in the control room of the housing
complex, and is used when a caretaker makes a call with the resident of each dwelling unit.
[0020]
In the intercom system for collective housing in the present embodiment, digitally modulated
audio information (audio data), video information (video data), and control information (control
data) are transmitted through transmission lines (main line L1, dwelling unit line L2, signal line
L3, Packets are transmitted via L4).
For example, in the lobby intercom, when the visitor operates the ten key switch or the touch
panel and receives the operation input of the dwelling unit number of any dwelling unit, the
packet in which the dwelling unit number is stored in the data field and the visitor imaged by the
imaging device Packets (video data) stored in the data field are transmitted (packet transmission)
to the address of the trunk control apparatus B via the signal line. The trunk control apparatus B
sends to the trunk L1 a control packet in which a call command for notifying a call from the
lobby interphone is stored in the data field and a video packet in which the video data is stored in
the data field. In the dwelling unit communication device A installed in the dwelling unit of the
dwelling unit number, when the control packet and the video packet are received through the
trunk line L1 and the dwelling unit line L2, the call command (control signal) stored in the data
field of the control packet Ring the ringer according to the speaker. In addition, the video data
stored in the data field of the video packet is processed to display the video of the visitor on a
display device such as a liquid crystal display. Then, when the resident who heard the ringing
sound operates a response button (not shown) of the dwelling unit communication device A, a
voice signal (transmission voice signal) output from the microphone is packet-transmitted
through the dwelling unit line L2. Similarly, also in the lobby intercom, a voice signal
(transmission voice signal) output from the microphone is packet-transmitted to the dwelling unit
talk device A via the trunk control device C. As a result, the resident of the dwelling unit and the
visitor can make an interphone call using the dwelling unit communication device A and the
lobby interphone.
11-04-2019
6
[0021]
Also, the control unit call unit C can be called from the dwell unit call unit A, and the resident and
the manager can talk using the unit control unit A and the control unit call unit C. In this case, a
packet including control data for calling the control room call device C is transmitted from the
dwell unit call device A, and the packet is transmitted to the control room call device C via the
trunk control device B. Then, when the handset (handset) of the control room call apparatus C is
off hook (or the call button is operated), voice data is transferred between the dwelling unit call
apparatus A and the control room call apparatus C as in the lobby interphone. Packets are
mutually transmitted. However, since the above-described dwell unit call device A, trunk control
device B, lobby interphone, and management room call device C can be realized using a
conventionally known technique, the illustration and description of the detailed configuration
will be omitted.
[0022]
Here, when there is a call from the dwelling unit call apparatus A to the control room call
apparatus C while the manager is absent, the call from the unit call apparatus A is transferred to
the mobile phone possessed by the manager and the reception center of the management
company. The transfer destination portable telephone and the telephone of the reception center
(hereinafter, these are called the external communication device F. It is desirable to transmit
voice between the housing unit A and the dwell unit communication device A to enable
communication. Therefore, the intercom system for collective housing in the present embodiment
is provided with the outside line transfer device E which mutually transfers the voice between the
dwelling unit communication device A and the external communication device F.
[0023]
As shown in FIG. 1, the external line transfer device E includes an automatic volume correction
device 1, a transmission processing unit 2, a two-line four-line converter 3, a receiving amplifier
4, a transmitting amplifier 5, an A / D converter 6, and a D / A. The converter 7 is provided. The
transmission processing unit 2 is connected to the trunk control device B via the signal line L4,
and performs packet transmission with the dwelling unit communication device A via the trunk
control device B.
11-04-2019
7
[0024]
The transmission processing unit 2 divides the voice signal (received voice data) output from the
automatic volume correction device 1 to create a packet, encodes the packet (voice packet), and
encodes the encoded bit string as an electric signal. And transmit to the signal line L4. The
transmission processing unit 2 converts (demodulates) the electrical signal transmitted to the
signal line L4 into a bit string, decodes the voice packet from the demodulated bit string, and
decodes the decoded voice signal (transmission voice data). Output to the D / A converter 7.
Then, the voice signal converted into an analog signal by the D / A converter 7 is amplified by
the transmission amplifier 5 and then output to the 2-wire 4-wire conversion unit 3. The two-line
to four-line conversion unit 3 is connected to the public telephone network N by the office line
(telephone line) Lx, and transmits the voice signal (transmission voice signal) amplified by the
transmission amplifier 5 to the telephone line Lx. The voice signal (reception voice signal)
transmitted through the telephone line Lx is output to the reception amplifier 4. The reception
voice signal amplified by the reception amplifier 4 is converted into a digital signal (reception
voice data) by the A / D converter 6 and is input to the automatic volume correction device 1.
[0025]
The automatic volume correction device 1 is realized by executing dedicated software with a
digital signal processor (DSP). The signal output unit 10, time average value calculation unit 11,
setting unit 12, selection unit 13, noise detection It has a part 14. However, these units 10 to 14
may be configured by independent circuit components. Further, in the following description, an
audio signal and a signal including sounds other than audio are generically called an acoustic
signal.
[0026]
The signal output unit 10 adjusts the signal level of the acoustic signal (acoustic data) output
from the A / D converter 6 and outputs the adjusted signal level to the transmission processing
unit 2. Here, “signal level” is data indicating sound volume (sound size) in sound data, and the
signal output unit 10 changes the data according to the adjustment amount set by the setting
unit 12 as described later. Adjust the signal level by In the following description, “adjustment
amount” is referred to as “gain”, and the signal level is higher (the volume is higher) as the
11-04-2019
8
“gain” is larger.
[0027]
The time average value calculator 11 is an input signal (an acoustic signal output from the A / D
converter 6). same as below. Time average value (long time average value PL) in a relatively long
time), time average value (short time average value PS) in a relatively short time of the input
signal, long time average value PL and short time average value PS And the time average value
(medium time average value Pn) in the middle time of Here, the time average value calculation
unit 11 stores the input signal input in a short time (buffer time) of, for example, about 16
milliseconds, and calculates the arithmetic average value of the input signal level for the buffer
time as the short time average value PS. Assuming that the arithmetic mean value of the input
signal level which is a fixed multiple (for example, 16 times) of the buffer time is the long time
average value PL, the arithmetic average value of the input signal level several times (for example
7 to 8 times) the buffer time Is the medium time average value Pn. However, the time average
value calculation unit 11 sets the short time average value PS so that the slope of the change of
the short time average value PS substantially matches the slope of the envelope when the sound
signal waveform (see FIG. 4A) rises. It is preferable to set a time width for calculating. Similarly,
the time average value calculation unit 11 calculates the long time average value PL so that the
slope of the change of the long time average value PL substantially matches the slope of the
envelope at the time of the falling of the acoustic signal waveform. It is preferable to set
[0028]
The selection unit 13 compares the long time average value PL calculated by the time average
value calculation unit 11 with the short time average value PS, and selects a short time average
value PS when PS ≧ PL, and PS <PL At this time, the long time average value PL is selected and
output to the setting unit 12.
[0029]
In general, it is considered that the short-time average value is mainly determined by the voice
component included in the input signal (acoustic signal), and the middle-time average value is
mainly the noise component (sound component other than voice) included in the input signal Is
considered to determine the level.
11-04-2019
9
Therefore, in the noise detection unit 14, if the ratio PS / Pn between the short time average
value PS calculated by the time average value calculation unit 11 and the medium time average
value Pn is 1 or more (PS / Pn ≧ 1), the noise is small. It detects (estimates) that (S / N ratio is
high), and detects (estimates) that there is a lot of noise (S / N ratio is low) if ratio PS / Pn is less
than 1 (PS / Pn <1). Then, the noise detection unit 14 outputs “1” to the setting unit 12 if it
detects that there is little noise, and “0” if it detects that there is much noise.
[0030]
The setting unit 12 selects one of three gains G1, G2 and G3 (G1> G2> G3) according to the time
average value (long time average value PL or short time average value PS) output from the
selection unit 13. Is set to the adjustment amount of the signal level and output to the signal
output unit 10. Then, the signal output unit 10 multiplies the signal level of the input signal by
the gain set by the setting unit 12 to output an acoustic signal whose signal level has been
adjusted to the transmission processing unit 2.
[0031]
FIG. 3 shows the volume correction characteristics in the automatic volume correction device 1,
where the horizontal axis represents the signal level of the input signal, and the vertical axis
represents the signal level of the output signal after volume correction. When the signal level of
the input signal is equal to or lower than the threshold value Th1 as shown in FIG. 3, the setting
unit 12 sets the gain to G1 to increase the volume, and the signal level of the input signal is
larger than the threshold value Th1. When the threshold value is less than Th2 (> Th1), the gain
is set to G2 and the volume is hardly adjusted. When the signal level of the input signal is larger
than the threshold value Th2, the setting unit 12 sets the gain to G3 (= 0) to reduce the volume.
[0032]
FIG. 4 (a) shows the waveform of the actual acoustic signal, and FIG. 4 (b) shows the envelope
(solid line X1) of the short-term average value PS and the selection when the acoustic signal of
FIG. The envelope (solid line X2) of the time average value f (PL, PS) output from the part 13 is
shown. For example, when the gain (adjustment amount) is set according to the short time
average value PS indicated by the solid line X1 in FIG. 4B, the rapid change in the signal level is
followed in a short time, and the gain changes one after another. As a result, there is a possibility
11-04-2019
10
that the sound signal may be intensified (volume increase or decrease). On the other hand, if gain
(adjustment amount) is set according to the short-time average value PS, although the intonation
of the acoustic signal can be suppressed, the volume may become too large without suppressing
the rapid rising of the signal level. There is.
[0033]
On the other hand, in the present embodiment, while the signal level of the input signal is rising,
the setting unit 12 sets the gain according to the short time average value PS selected by the
selection unit 13 while the signal level of the input signal is falling Since the setting unit 12 sets
the gain according to the long time average value PL selected in 13, the fluctuation range of the
gain is reduced to reduce the intonation of the acoustic signal and the peak of the sound volume
is within the appropriate range. Can. That is, according to the automatic volume correction device
1 of the present embodiment, it is possible to automatically correct the volume of the sound
signal to an easy-to-hear volume by suppressing the intonation of the sound signal.
[0034]
By the way, if the condition (threshold values Th1 and Th2) for the setting unit 12 to change the
setting of the gain Gi (i = 1, 2, 3) at the rising time and the falling time of the signal level is the
same, the signal level is If the gain Gi changes frequently when fluctuating around the threshold
values Th1 and Th2, the volume may increase or decrease. Therefore, in the setting unit 12, it is
preferable that the threshold values Th1 and Th2 have hysteresis, and the threshold values Th11,
Th12, Th21, and Th22 be made different between when the signal level rises and falls. For
example, as shown in FIG. 5, the threshold values Th12 and Th22 at the time of falling of the
signal level may be smaller (lower) than the threshold values Th11 and Th21 at the time of rising
of the signal level. In this way, even if the signal level fluctuates in the vicinity of the threshold
value, it is possible to suppress a rapid increase and decrease in sound volume (toning of the
acoustic signal).
[0035]
Here, while the signal level is falling, the gain is adjusted according to the long time average
value PL, but the gain is changed from G2 to G1 in a much shorter time than the calculation time
of the long time average value PL If so, the sound volume may be increased more than necessary
11-04-2019
11
and the sound signal may be depressed. Therefore, when the setting unit 12 changes the gain in
the direction of increasing the signal level, if the gain is gradually changed as shown in FIG. 6, the
sound volume may be increased more than necessary and the acoustic signal may be depressed.
It can prevent.
[0036]
On the other hand, since the gain is adjusted according to the short time average value PS while
the signal level is rising, the gain is slowly changed from G2 to G3 in a longer time than the
calculation time of the short time average value PS. And, there is a possibility that the sound
signal may be touted without being able to follow the increase and decrease of the volume.
Therefore, when the setting unit 12 changes the gain in the direction to decrease the signal level,
if the gain is rapidly changed as shown in FIG. 7, the acoustic signal may not be able to follow the
increase or decrease of the volume. It can prevent.
[0037]
By the way, when the signal level of the input signal is adjusted, the signal level of the noise
component (ambient noise) included in the input signal is also adjusted at the same time. There is
a possibility of Therefore, in the present embodiment, when the noise detection unit 14 estimates
that there is a large amount of noise, the setting unit 12 outputs the input signal as it is (through)
without setting the gain, and the noise detection unit 14 has a small amount of noise. The setting
unit 12 sets the gain only when it is estimated. That is, the setting unit 12 does not set the gain
when the output signal of the noise detection unit 14 is “0”, and sets the gain only when the
output signal of the noise detection unit 14 is “1”. Thereby, it is possible to suppress the
negative effect of the volume correction that the target sound is disturbed by the ambient noise
and it becomes difficult to hear.
[0038]
Here, a noise suppressor (noise canceller) 15 may be provided to suppress noise (ambient noise)
other than voice contained in the input signal. The noise canceller 15 is well known in the prior
art and suppresses and outputs only the signal component of the ambient noise from the input
signal in which the call voice and the ambient noise are mixed. Therefore, when it is estimated by
the noise detection unit 14 that there is much noise (when the output signal of the noise
11-04-2019
12
detection unit 14 is “0”), the noise canceller 15 suppresses only the signal component of
ambient noise from the input signal to By improving the N ratio, it is possible to prevent the
target sound from being disturbed by ambient noise and becoming difficult to hear. However,
when it is estimated by the noise detection unit 14 that there is little noise (when the output
signal of the noise detection unit 14 is “1”), the noise canceller 15 may be stopped.
[0039]
1 Automatic Volume Correction Device 10 Signal Output Unit 11 Hourly Average Value
Calculation Unit 12 Setting Unit
11-04-2019
13
Документ
Категория
Без категории
Просмотров
0
Размер файла
23 Кб
Теги
description, jp2012129741
1/--страниц
Пожаловаться на содержимое документа