JP2001268213A - Voice communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice commutation device that can avoid deterioration due to an intermittent sense of voice in advance, even when a surrounding noise level is comparatively high and can fully cancel a voice echo, even when the surrounding noise level is comparatively small. SOLUTION: An echo suppress control circuit 5 discriminates a surrounding noise level, by discriminating a detection result notice outputted by a surrounding noise level detection circuit 4 and sets attenuation of the level of a transmission signal, in response to the surrounding noise level to attenuate the level of the transmission signal. Even when the surrounding noise level is comparatively high, the device can avoid in advance deterioration due to an intermittent sense of voice and when the surrounding noise level is comparatively small, the device can fully cancel the voice echo.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice communication device configured to enable hands-free communication.

[0002]

Conventionally, there has been provided a voice communication apparatus having a hands-free function for realizing hands-free communication. What is a hands-free call?
Separately from the handset, a speaker that outputs the reception sound and a microphone that inputs the transmission sound are arranged, for example, on the dashboard in the car, so that it is not necessary to have a handset, and it is possible to make a call. This allows the user to ensure safety during driving.

[0003] In such a hands-free call, when a received sound output from a speaker is input to a microphone and transmitted to the other party, an acoustic echo may be generated. If you do
There is a problem that the call is hindered. Therefore, this type of voice communication device generally has an echo canceller function, and is configured to be able to cancel an acoustic echo caused by a reception sound output from a speaker being input to a microphone. ing.

However, when the volume of the received sound is extremely large, there is a problem that the acoustic echo cannot be sufficiently canceled only by operating the echo canceller function. Thus, in recent years, a configuration in which the above-described echo canceller function and echo suppress function are used in combination has been provided. In this case, the echo suppress function attenuates the level of the transmission signal output from the microphone in accordance with a predetermined attenuation amount on condition that the apparatus is in the receiving state, and then transmits the transmission signal to the communication partner side. It is.

[0005] However, such a conventional device has the following disadvantages since the amount of attenuation for attenuating the level of the transmission signal is constant.

That is, if the ambient noise level in the voice communication apparatus is relatively large, the acoustic echo is mixed with the ambient noise, so that the acoustic echo can be sufficiently canceled. However, there was a problem that was deteriorated. Conversely, if the ambient noise level in the voice communication device is relatively small, the transmitted voice will not be mixed with the ambient noise, so the sense of interruption of the voice will be improved, but on the other hand, There was a problem that the acoustic echo could not be canceled sufficiently.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the deterioration of the sense of discontinuity of sound even when the ambient noise level is relatively large. Another object of the present invention is to provide a voice communication device that can sufficiently cancel an acoustic echo even when the ambient noise level is relatively small, thereby improving usability.

[0008]

According to the first aspect of the present invention, the receiving sound output means receives the receiving signal and outputs the receiving sound, and the transmitting sound input means outputs the transmitting sound. The echo canceller cancels the acoustic echo caused by the reception sound output from the reception sound output means being input to the transmission sound input means. Further, the ambient noise level detecting means detects the ambient noise level, and the control means responds to the detection result of the ambient noise level detecting means on condition that the receiving state detecting means detects the receiving state. Setting the amount of attenuation of the level of the transmission signal in the transmission signal attenuating means to operate the transmission signal attenuating means, and the transmitting signal attenuating means reduces the level of the transmission signal output from the transmission sound input means. Decay.

In other words, according to this configuration, the level of the transmission signal is attenuated by setting the attenuation of the level of the transmission signal in accordance with the ambient noise level. Even if the ambient noise level is relatively high, it is possible to avoid the deterioration of the sense of discontinuity of the sound, and even if the ambient noise level is relatively low, the acoustic echo is sufficiently canceled. can do. Thereby, usability can be improved.

According to the second aspect of the present invention, when the ambient noise level detecting means detects that the ambient noise level is relatively large, the control means controls the level of the transmission signal in the transmission signal attenuating means. The transmission signal attenuating means is operated with the attenuation set relatively small, and when the ambient noise level detecting means detects that the ambient noise level is relatively small, the level of the transmission signal is attenuated by the transmission signal attenuating means. The transmission signal attenuating means is operated with the amount set relatively large.

That is, according to this, when the ambient noise level is relatively large, the level of the transmission signal is attenuated by setting the level of attenuation of the transmission signal to be relatively small,
On the other hand, when the ambient noise level is relatively low, the level of the transmission signal level is set to be relatively large to attenuate the level of the transmission signal. Even if the level is relatively high, it is possible to avoid the deterioration of the sense of discontinuity of the sound, and even if the ambient noise level is relatively low, it is possible to sufficiently cancel the acoustic echo. it can.

According to the third aspect of the present invention, when the control means determines that the volume of the received sound output from the received sound output means is lower than the predetermined level, the control means controls the operation of the transmission signal attenuating means. Stop.

In other words, according to this configuration, when it is determined that the volume of the received sound is lower than the predetermined level, the operation of the transmission signal attenuating means is stopped, so that the volume of the received sound is extremely low. In such a case, if the acoustic echo can be sufficiently canceled only by operating the echo canceller function, it is possible to prevent the transmission signal attenuating means from being operated unnecessarily.

According to the fourth aspect of the present invention, the control means can change the amount of attenuation of the transmission signal level in the transmission signal attenuating means.

In other words, according to this configuration, since the level of attenuation of the transmission signal in the transmission signal attenuating means can be changed, the attenuation of the level of the transmission signal is optimized according to, for example, the form of the system. It is possible to flexibly cope with it, for example, it can be set to a suitable value, and it is also possible to expand the use form.

[0016]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a functional block diagram of a portion according to the gist of the present invention. In the voice communication device 1, first, a transmission system will be described. When a microphone 2 (transmission sound input means in the present invention) inputs a voice uttered by a user as a transmission sound, the microphone 2 converts the input transmission sound into a voice. Processing is performed to generate a transmission signal, and the generated transmission signal is output to the transmission amplifier 3.

When a transmission signal is input from the microphone 2, the transmission amplifier 3 amplifies the input transmission signal and transmits the amplified transmission signal to an ambient noise level detection circuit 4 (ambient noise level detecting means in the present invention). ). When a transmission signal is input from the transmission amplifier 3, the ambient noise level detection circuit 4 integrates the level of the input transmission signal to obtain
An ambient noise level included in the transmission signal is detected, and a detection result notification indicating the detection result is output to the echo suppression control circuit 5 (control means in the present invention).

When the transmission signal is input from the ambient noise level detection circuit 4, the echo canceller 6 performs echo cancellation processing on the input transmission signal in relation to the reception signal, and transmits the transmission signal subjected to the echo cancellation processing to the transmission electronic signal. Output to volume 7 (transmitted signal attenuating means in the present invention).

When a transmission signal is input from the echo canceller 6, the transmission electronic volume 7 attenuates the level of the input transmission signal and transmits the level-attenuated transmission signal to the portable telephone (as described later in detail). (Not shown). Then, when a transmission signal is input from the transmission electronic volume 7, the wireless circuit of the mobile phone wirelessly processes the input transmission signal.

Next, a receiving system will be described. When a receiving signal is input from a wireless circuit of a portable telephone, the receiving amplifier 8 amplifies the input receiving signal and outputs the amplified receiving signal to the echo canceller 6. Echo canceller 6
Receives a reception signal from the reception amplifier 8, performs echo cancellation processing on the input reception signal in relation to the transmission signal, and outputs the reception signal subjected to the echo cancellation processing to the reception electronic volume 9.

When the reception electronic volume 9 receives a reception signal from the echo canceller 6, the level of the received reception signal is attenuated, and the received reception signal whose level has been attenuated is transmitted to a speaker 10 (referred to in the present invention) as described later in detail. Receiving sound output means). Then, when the receiving signal is input from the receiving electronic volume 9, the speaker 10 processes the input receiving signal to generate a receiving sound, and outputs the generated receiving sound.

In the above configuration, the echo canceller 6 includes an adaptive filter, an adding circuit, a ROM, and the like.
By performing echo cancellation processing on the transmission signal and the reception signal using M, the acoustic echo caused by the reception sound output from the speaker 10 being input to the microphone 2 is canceled.

The receiving state detecting circuit 11 (receiving state detecting means according to the present invention) includes: a level of a transmitting signal output from the echo canceller 6 and input to the transmitting electronic volume 7;
By comparing the level of the reception signal output from the reception amplifier 8 and input to the echo canceller 6, it is detected whether or not the reception state is established. If the reception state is detected, the reception state is determined. The received reception status notification is output to the echo suppression control circuit 5 described above.

The volume switch 12 is capable of mechanically setting the volume of a received sound in response to the operation of the up switch 12a or the down switch 12b by the user. The up switch 12a or the down switch 12b Is operated, a volume setting command indicating a set value set in accordance with the operation is output to the above-described echo suppression control circuit 5.

When a volume setting command is input from the volume switch 12, the echo suppression control circuit 5 outputs a volume control command to the receiving electronic volume 9 in accordance with the input volume setting command. Then, the reception electronic volume 9 attenuates the level of the reception signal input from the echo canceller 6 in accordance with the volume control command input from the echo suppression control circuit 5. With such a configuration, the user can adjust the volume of the reception sound output from the speaker 10 by operating the volume switch 12.

The echo suppression control circuit 5 is provided in the
As shown in the figure, the set value (volume set value) of the volume switch 12 and the attenuation of the level of the transmission signal in the transmission electronic volume 7 (echo suppression attenuation)
And a table corresponding to. Here, the echo suppression control circuit 5 sets the echo suppression attenuation to be different from each other according to the level of the ambient noise level as the echo suppression attenuation.

When a volume setting command is input from the volume switch 12, the echo suppress control circuit 5 responds to the input volume setting command and a detection result notification input from the ambient noise level detection circuit 4 to the corresponding echo suppress control. The attenuation is read, and an echo suppression control command indicating the read echo suppression attenuation is output to the transmission electronic volume 7. Then, the transmission electronic volume 7 attenuates the level of the transmission signal input from the echo canceller 6 according to the echo suppression control command input from the echo suppression control circuit 5.

In this case, the echo suppression control circuit 5
Sets the volume setting value of the volume switch 12 to five levels of “1” to “5”. When the volume setting value of the volume switch 12 is “3” or more, the ambient noise level is relatively large. The value of the echo suppression attenuation in the case of
B ", and the value of the echo suppression attenuation when the ambient noise level is medium is set to" -9.0 dB ". The value of the echo suppression attenuation amount in the case of a relatively small degree is set to a constant value of "-12.0 dB".

The echo suppression control circuit 5 determines that the volume set value of the volume switch 12 is "2".
Below (below the predetermined level in the present invention)
By setting the value of the echo suppression attenuation amount to "0.0 dB", the level of the transmission signal is not attenuated, that is, the echo suppression function is stopped.
Further, the echo suppression control circuit 5 can freely change the value of the echo suppression attenuation amount with respect to these volume setting values.

Next, the operation of the above configuration will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG. When receiving the detection result notification from the ambient noise level detection circuit 4, the echo suppression control circuit 5 determines the ambient noise level indicated by the input detection result notification (step S1). When receiving a volume setting command from the volume switch 12, the echo suppression control circuit 5 determines the volume setting value indicated by the input volume setting command (step S2).

Here, the echo suppression control circuit 5 determines that the volume setting value is "2" if the volume setting value is equal to or less than a value at which the echo suppression function should be activated.
If it is less than or equal to the above, "NO" is determined in the step S3, the process returns to the step S1, and the ambient noise level is determined again.

On the other hand, if the volume setting value exceeds the value at which the echo suppression function is to be activated, the echo suppression control circuit 5 specifically sets the volume setting value to "3".
If it is the above, it is determined as "YES" in step S3, and it is determined whether or not the receiving state notification is input from the receiving state detecting circuit 11 to determine whether or not the receiving state is established (step S4). ).

Here, the echo suppression control circuit 5 has not received the receiving state notification from the receiving state detecting circuit 11, and if it is not in the receiving state, it returns "N" in step S4.
O ", the process returns to step S1, and the ambient noise level is determined again.

On the other hand, the echo suppression control circuit 5 has received the reception state notification from the reception state detection circuit 11, and if it is in the reception state, it determines "YES" in step S4, With reference to a table corresponding to the suppression attenuation amount (step S5),
The echo suppression attenuation is determined according to the volume setting value indicated by the input volume setting command and the ambient noise level indicated by the input detection result notification (step S6).

Then, the echo suppression control circuit 5 outputs the echo suppression control command to the transmission electronic volume 6 to attenuate the level of the transmission signal in accordance with the determined echo suppression attenuation (step S7). Then, the process returns to step S1, and thereafter, the same processing is repeated and executed.

In the configuration described above, the echo suppression attenuation is changed stepwise in accordance with the stepwise setting of the volume setting value.
If the volume setting can be set continuously,
It is also possible to continuously change the amount of echo suppression attenuation.

The value of the echo suppression attenuation with respect to the volume set value may be set to an optimum value according to an experimental value or an empirical value.

As described above, according to the first embodiment, the echo suppression control circuit 5 determines the ambient noise level by determining the notification of the detection result output from the ambient noise level detection circuit 4, and determines the ambient noise level. Since the level of the transmission signal is attenuated by setting the amount of attenuation of the level of the transmission signal according to the noise level, unlike the conventional case, the ambient noise level is relatively large. Also,
Deterioration of the sense of discontinuity of voice can be avoided beforehand, and even when the ambient noise level is relatively small, acoustic echo can be sufficiently canceled. Thereby, usability can be improved.

When the echo suppression control circuit 5 determines that the volume of the received sound output from the speaker 10 is equal to or lower than a predetermined level, specifically, the volume setting value is equal to or lower than “2”, the transmission is stopped. The echo suppression function is stopped by setting the attenuation amount of the level of the speech signal to "0.0 dB", so that the echo canceller function is activated even when the volume of the received sound is extremely low. In a case where the acoustic echo can be sufficiently canceled only by using the echo cancel function, it is possible to prevent the unnecessary operation of the echo suppress function.

Further, since the echo suppression control circuit 5 is configured to be able to freely change the value of the echo suppression attenuation with respect to the volume set value and the level of the ambient noise level, the echo suppression control circuit 5 can be used, for example, in accordance with the form of the system. It is possible to flexibly cope with, for example, it is possible to set the amount of attenuation to an optimum value, and it is also possible to expand the use form.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
An embodiment will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, different parts will be described.

In the first embodiment, when the volume setting value of the volume switch 12 is equal to or more than "3", the echo suppression control circuit 5 sets the echo suppression attenuation value to "-6.0 dB" or "-6.0 dB". In contrast, in the second embodiment, when the volume setting value of the volume switch 12 is equal to or more than “3”, it is set as “9.0 dB” or “−12.0 dB”. When the volume setting value of the volume switch 12 is relatively large, the value of the echo suppression attenuation is set to a relatively large value so that the attenuation of the level of the transmission signal is relatively large.
When the volume setting value of the volume switch 12 is relatively small, the value of the echo suppression attenuation is set to a relatively small value so that the attenuation of the level of the transmission signal is relatively small.

More specifically, when the volume setting value of the volume switch 12 is "3", the echo suppression control circuit 5 sets the value of the echo suppression attenuation amount when the ambient noise level is relatively large to "3". −3.0 dB ”, and the value of the echo suppression attenuation when the ambient noise level is medium is set as“ −4.5 dB ”. The value of the echo suppression attenuation amount in the case of extremely small value is set as “−6.0 dB”.

The echo suppression control circuit 5 determines that the volume set value of the volume switch 12 is "4".
, The value of the echo suppression attenuation when the ambient noise level is relatively large is “−4.5d”.
B ”, and the value of the echo suppression attenuation when the ambient noise level is medium is set to“ −6.75 dB ”, and the ambient noise level is relatively small. In this case, the value of the echo suppression attenuation amount is set to "-9.0 dB".

Further, when the volume setting value of the volume switch 12 is "5", the echo suppression control circuit 5 sets the value of the echo suppression attenuation when the ambient noise level is relatively large to "-".
6.0 dB ", and the value of the echo suppression attenuation when the ambient noise level is moderate is set to" -9.0 dB ". Further, the ambient noise level is relatively low. The value of the echo suppression attenuation in the case of a small degree is set to "-12.0 dB".

As described above, according to the second embodiment, the same functions and effects as those of the above-described first embodiment can be obtained. In this case, in particular, in this case, the one described in the above-mentioned first embodiment can be obtained. When the volume setting value is relatively large, that is, when the volume of the received sound is relatively large,
Since the level of the transmitted signal is attenuated by setting the level of the transmitted signal to be relatively large, the acoustic echo is accurately canceled even when the volume of the received sound is relatively large. On the other hand, when the volume setting value is relatively low, that is, when the volume of the received sound is relatively low, the level of the transmission signal is attenuated by setting the level of attenuation of the transmission signal to a relatively low level. With such a configuration, even when the volume of the received sound is relatively low, it is possible to accurately prevent the deterioration of the sense of interruption in the sound.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
An embodiment will be described with reference to FIGS.
The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, different parts will be described.

In the first embodiment described above, the echo suppression control circuit 5 receives a volume setting command from the volume switch 12 and determines only the volume setting value mechanically set by the volume switch 12. In contrast to this, in the third embodiment, the volume set value mechanically set by the volume switch 12 and the volume of the received signal are determined. The sound volume of the received sound is estimated and calculated based on the relationship with the level, and the calculation result is determined to determine the sound volume of the received sound.

More specifically, in the voice communication device 21, when a volume setting command is input from the volume switch 12, the reception volume calculation circuit 22 integrates the level of the reception signal input from the echo canceler 5, thereby obtaining a volume. The volume of the received sound is estimated and calculated based on the relationship between the volume setting value indicated by the volume setting command input from the switch 12 and the integration result obtained by integrating the level of the reception signal input from the echo cancel 5, and the calculation result is calculated. The notification of the speaker output level is output to the echo suppression control circuit 23 (control means in the present invention).

As shown in FIG. 6, the echo suppression control circuit 23 outputs the output level of the speaker 9 (speaker output level), the attenuation of the transmission signal level in the transmission electronic volume 6 (echo suppression attenuation), and Is held. Here, the echo suppression control circuit 23 differs from the echo suppression control circuit 5 described in the first embodiment in terms of the amount of echo suppression attenuation as the amount of echo suppression attenuation according to the level of the ambient noise level. Is set as follows.

Then, the echo suppression control circuit 23
When a speaker output level notification is input from the receiving sound volume calculation circuit 22, the corresponding echo suppress attenuation is read out according to the input speaker output level notification and the detection result notification input from the ambient noise level detection circuit 4, and the read echo is read out. An echo suppression control command indicating the amount of suppression attenuation is output to the transmission electronic volume 7. The transmission electronic volume 7 attenuates the level of the transmission signal input from the echo canceller 6 according to the echo suppression control command input from the echo suppression control circuit 23 in the same manner as in the first embodiment. Here, the echo suppression control circuit 23 sets the speaker output level in the reception sound volume calculation circuit 22 to five levels.

Further, the receiving volume calculating circuit 22 receives a volume setting command from the volume switch 12,
A volume control command is output to the receiving electronic volume 24 according to the input volume setting command. Then, the reception electronic volume 24 attenuates the level of the reception signal input from the reception volume calculation circuit 22 according to the volume control command input from the reception volume calculation circuit 22. With such a configuration, the user operates the volume switch 12 in the same manner as in the first embodiment,
It is possible to adjust the volume of the reception sound output from the speaker 10.

Next, the operation of the above configuration will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG. When receiving the detection result notification from the ambient noise level detection circuit 4, the echo suppression control circuit 23 determines the ambient noise level indicated by the input detection result notification (step S11). Then, when receiving the speaker output level notification from the receiving sound volume calculation circuit 22, the echo suppression control circuit 23 determines the speaker output level indicated by the input speaker output level notification (step S12).

Here, the echo suppression control circuit 23
If the speaker output level is equal to or less than the value at which the echo suppress function should be activated, specifically, if the speaker output level is equal to or less than “150 dBm”, “NO” is determined in step S13, and the process returns to step S11 described above.
The ambient noise level is determined again.

On the other hand, if the loudspeaker output level exceeds the value at which the echo suppress function should be activated, specifically, if the loudspeaker output level exceeds "150 dBm", the echo suppressor control circuit 23 proceeds to step S13. By determining "YES" and determining whether or not the receiving state notification has been input from the receiving state detecting circuit 9,
It is determined whether or not it is in the receiving state (step S14).

Here, the echo suppression control circuit 23
If the receiving state notification is not input from the receiving state detecting circuit 11 and the receiving state is not the receiving state, "N" is determined in step S14.
O "and returns to step S11 described above.
Determine the ambient noise level.

On the other hand, the echo suppression control circuit 23 receives the reception state notification from the reception state detection circuit 11,
If it is in the receiving state, "YES" in step S14.
Is determined, and the above-mentioned table in which the speaker output level and the echo suppression attenuation amount correspond to each other is referred to (step S
15) The echo suppression attenuation is determined according to the speaker output level indicated by the input speaker output level notification and the ambient noise level indicated by the input detection result notification (step S16).

Then, the echo suppress control circuit 23
By outputting the echo suppression control command to the transmission electronic volume 6, the level of the transmission signal is attenuated in accordance with the determined echo suppression attenuation (step S17).
The process returns to step S11, and thereafter, the same processing is repeated and executed.

Also in this case, the value of the echo suppression attenuation amount with respect to the speaker output level may be set to an optimum value according to an experimental value or an empirical value.

As described above, according to the third embodiment, the same operation and effect as those of the first embodiment can be obtained. In this case, in particular, in this case, the volume switch 12 The sound volume of the received sound is estimated and calculated based on the relationship between the volume set value mechanically set in step (1) and the level of the received signal, and the calculation result in the echo suppression control circuit 23 is determined. Since the configuration is such that the volume of the received sound is determined, the accuracy in determining the volume of the received sound can be improved as compared with the first embodiment described above.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.
An embodiment will be described with reference to FIG. The same parts as those in the third embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Hereinafter, different parts will be described.

In the third embodiment, the echo suppression control circuit 23 sets the value of the echo suppression attenuation amount to "-6.0 dB" when the speaker output level in the reception volume calculation circuit 22 exceeds "150 dBm". ,
The value is fixedly set as "-9.0 dB" or "-12.0 dB".
In the embodiment, when the speaker output level in the receiving sound volume calculation circuit 22 exceeds “150 dBm”, when the speaker output level is relatively large, the echo suppression is performed so that the attenuation of the transmission signal level is relatively large. When the attenuation value is set to a relatively large value, while the speaker output level is relatively small, the echo suppression attenuation value is compared so that the attenuation of the transmission signal level is relatively small. It is set to a very small value.

As described above, according to the fourth embodiment, the same functions and effects as those of the above-described third embodiment can be obtained. In this case, in particular, in this case, the effects described in the above-described third embodiment can be obtained. When the speaker output level is relatively large, that is, when the volume of the received sound is relatively large, the level of the transmitted signal is attenuated by setting the level of attenuation of the transmitted signal to be relatively large. With this configuration, in the same manner as described in the second embodiment, even when the volume of the received sound is relatively large, the acoustic echo can be accurately canceled. When the volume of the received sound is relatively small, that is, when the volume of the received sound is relatively small, the level of the transmission signal is attenuated by setting the level of attenuation of the transmission signal to be relatively small. In a manner similar to that described in 施例, even if the volume of the reception sound is relatively small, it is possible to precisely avoid in advance the deterioration of feeling, audio interruption.

(Other Embodiments) The present invention is not limited to the above embodiment, but can be modified or expanded as follows. The present invention is not limited to the configuration in which the volume setting value and the speaker output level can be set in five levels, but may be a configuration in which the volume setting value and the speaker output level can be set in any number of levels.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a main part of a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a volume setting value and an echo suppression attenuation amount.

FIG. 3 is a flowchart showing control contents.

FIG. 4 is a view corresponding to FIG. 2, showing a second embodiment of the present invention;

FIG. 5 is a functional block diagram showing a main part of a third embodiment of the present invention.

FIG. 6 is a diagram showing the relationship between the speaker output level and the amount of echo suppression attenuation.

FIG. 7 is a diagram corresponding to FIG. 3;

FIG. 8 is a view corresponding to FIG. 6, showing a fourth embodiment of the present invention.

[Explanation of symbols]

In the drawings, 1 is a voice communication device, 2 is a microphone (transmitted sound input means), 4 is an ambient noise level detection circuit (ambient noise level detection means), 5 is an echo suppression control circuit (control means), and 6 is an echo canceller. , 7 is a transmission electronic volume (transmission signal attenuating means), 10 is a speaker (reception sound output means), 11 is a reception state detection circuit (reception state detection means),
21 is a voice communication device, and 23 is an echo suppression control circuit (control means).

Continued on the front page F term (reference) 5K027 AA16 BB03 BB07 DD08 DD10 DD14 DD16 DD18 FF16 FF22 HH03 MM04 MM17 5K046 AA05 BA05 BB01 HH11 HH13 HH61 HH69 HH71 HH79

Claims (4)

[Claims] 1. A receiving sound output means for receiving a receiving signal and outputting a receiving sound, and a transmitting sound for inputting a transmitting sound and outputting a transmitting signal. Input means; an echo canceller for canceling an acoustic echo caused by a received sound output from the received sound output means being input to the transmitted sound input means; and a transmission output from the transmitted sound input means. A transmission signal attenuating means for attenuating a signal level, a receiving state detecting means for detecting whether or not a receiving state is provided, and a condition that the receiving state detecting means detects the receiving state. A voice communication device comprising: control means for operating the transmission signal attenuating means; and an ambient noise level detecting means for detecting an ambient noise level, wherein the control means comprises: the ambient noise level detecting means. Voice communication device characterized by operating the transmission signal attenuating means to set the attenuation level of the transmission signal in the transmission signal attenuation means according to the detection result. 2. The control means, when the ambient noise level detecting means detects that the ambient noise level is relatively high, sets the attenuation of the level of the transmission signal in the transmission signal attenuation means to be relatively small. Operating the transmission signal attenuating means, and when the ambient noise level detecting means detects that the ambient noise level is relatively low, the amount of attenuation of the level of the transmission signal in the transmission signal attenuating means is relatively reduced. 2. The voice communication device according to claim 1, wherein the transmission signal attenuating means is operated with a large setting. 3. The method according to claim 2, wherein the control means stops the operation of the transmission signal attenuating means when it is determined that the volume of the reception sound output from the reception sound output means is lower than a predetermined level. The voice communication device according to claim 1. 4. The voice communication apparatus according to claim 1, wherein said control means is capable of changing the amount of attenuation of the level of the transmission signal in said transmission signal attenuating means.