JP2001211249A - Voice communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice communication unit that can fully cancel acoustic echoes, even when a volume of a received sound is comparatively high and prevent deterioration in voice, denoting a sense of intermittent voice in advance, even when the volume of the received sound is comparatively low. SOLUTION: An echo suppression control circuit 10 gives an echo suppression control command to a transmission electronic volume 5, so as to comparatively increase an attenuation of a level of a transmission signal, when it is discriminated that the volume of a sound outputted from a loudspeaker 8 is comparatively high. On the other hand, it gives an echo suppression control command to the transmission electronic volume 5, so as to comparatively decrease the attenuation of the level of the transmission signal when it is discriminated that the volume of the sound outputted from the speaker 8 is comparatively low.

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]

For example, an in-vehicle telephone device mounted on a car, for example, generally has a hands-free function that enables hands-free communication.
With hands-free calling, apart from the handset, by disposing a speaker that outputs the reception sound and a microphone that inputs the transmission sound on, for example, the dashboard in the car, it became unnecessary to have a handset, This makes it possible to make a telephone call, thereby enabling 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 telephone device generally has an echo canceller function, and is configured to be able to cancel an acoustic echo caused by a received sound output from a speaker being input to a microphone. I have.

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, in the conventional configuration using both the echo canceller function and the echo suppress function, the attenuation amount for attenuating the level of the transmission signal is constant. There was a problem.

That is, when the amount of attenuation for attenuating the level of the transmission signal is set to a relatively small value,
If the attenuation of the level of the transmission signal is relatively small, the sense of interruption of the sound is improved, but if the volume of the reception sound output from the speaker is relatively large, the transmission Since the attenuation of the signal level is relatively small, there is a problem that the acoustic echo cannot be sufficiently canceled.

On the other hand, on the other hand, when the attenuation for attenuating the level of the transmission signal is set to a relatively large value, that is, when the attenuation of the level of the transmission signal is relatively large. Although the acoustic echo can be sufficiently canceled, on the other hand, at this time, if the volume of the received sound output from the speaker is relatively small, the attenuation of the level of the transmission signal is relatively large. However, there is a problem that the sense of interruption of the sound is deteriorated.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to sufficiently cancel an acoustic echo even when the volume of a received sound is relatively large. It is an object of the present invention to provide a voice communication device capable of avoiding deterioration of a sense of discontinuity of voice even when the volume of a received sound is relatively low, thereby improving usability.

[0009]

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 control means operates the transmission signal attenuating means on condition that the reception state detecting means detects the receiving state, and the transmission signal attenuating means is output from the transmission sound input means. The level of the transmitted transmission signal.

At this time, when the control means determines that the volume of the received sound output from the received sound output means is relatively large, the control means sets the level of attenuation of the transmission signal in the transmission signal attenuating means to relatively low. The transmission signal attenuating means is operated in the increased state, and when it is determined that the volume of the reception sound output from the reception sound output means is relatively low, the amount of attenuation of the level of the transmission signal in the transmission signal attenuating means. The transmission signal attenuating means is operated in a state where is relatively small.

That is, according to this configuration, when it is determined that the volume of the received sound is relatively large, the level of the transmission signal is attenuated with the level of attenuation of the level of the transmission signal relatively large. Therefore, unlike the conventional one, even if the volume of the received sound is relatively large, the acoustic echo can be sufficiently canceled because the level of the transmission signal is relatively attenuated. On the other hand, when it is determined that the volume of the received sound is relatively low, the level of the transmission signal is attenuated in a state where the attenuation of the level of the transmission signal is relatively small. Even when the volume of the received sound is relatively low, the level of attenuation of the transmission signal is relatively small, so that it is possible to avoid the deterioration of the sense of discontinuity of the sound. This allows
Usability can be improved.

According to the second 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 third aspect of the present invention, the receiving sound volume setting means can mechanically set the receiving sound volume, and the control means determines the set value in the receiving sound volume setting means. The volume of the received sound output from the received sound output means is determined.

[0015] That is, according to this configuration, the sound volume of the received sound is determined by determining the set value mechanically set by the received sound volume setting means. The volume of the received sound can be determined.

According to the fourth aspect of the present invention, the receiving sound volume setting means can mechanically set the sound volume of the receiving sound, and the receiving sound volume calculating means includes the setting value in the receiving sound volume setting means and the receiving signal. The volume of the received sound output from the received sound output means is estimated and calculated based on the relationship with the level of the received sound. Then, the control means determines the volume of the received sound output from the received sound output means by determining the result of the calculation by the received sound volume calculating means.

That is, according to this, not only the set value mechanically set by the receiving volume setting means, but also
The sound volume of the received sound is estimated by calculating and estimating the sound volume of the received sound based on the relationship between the setting value mechanically set by the received sound volume setting means and the level of the received signal, and determining the calculation result. With this configuration, it is possible to improve the accuracy in determining the volume of the received sound as compared with the above-described third embodiment.

According to the fifth aspect of the present invention, the receiving state detecting means detects whether or not the receiving state is established by comparing the level of the receiving signal with the level of the transmitting signal.

That is, according to this configuration, it is configured to detect whether or not the receiving state is established by comparing the level of the receiving signal with the level of the transmitting signal. Based on the comparison result with the level of the speech signal, it is possible to accurately detect whether or not the apparatus is in the receiving state.

According to the voice communication device of the sixth aspect, the control means can change the amount of attenuation of the level of the transmission signal 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.

[0022]

(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 the transmission signal is input from the microphone 2, the transmission amplifier 3 amplifies the input transmission signal and outputs the amplified transmission signal to the echo canceller 4. When a transmission signal is input from the transmission amplifier 3, the echo canceller 4 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 volume 5 (the present invention). (Transmission signal attenuating means).

When a transmission signal is input from the echo canceller 4, the transmission electronic volume 5 attenuates the level of the input transmission signal and transmits the reduced transmission signal to a radio circuit (described later). (Not shown). Then, when a transmission signal is input from the transmission electronic volume 5, the wireless circuit wirelessly processes the input transmission signal.

Next, the reception system will be described. The reception amplifier 6 receives a reception signal from a wireless circuit, amplifies the input reception signal, and outputs the amplified reception signal to the echo canceller 4. The echo canceller 4, upon receiving a reception signal from the reception amplifier 6, 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 7.

When a receiving signal is input from the echo canceller 4, the receiving electronic volume 7 attenuates the level of the input receiving signal and outputs the received signal with the level attenuated to the speaker 8 (referred to in the present invention) as described in detail later. Receiving sound output means). Then, when the receiving signal is input from the receiving electronic volume 7, the speaker 8 processes the input receiving signal to generate a receiving sound, and outputs the generated receiving sound.

In the configuration described above, the echo canceller 4 includes an adaptive filter, an adder, a ROM, and the like.
The echo cancellation processing of the transmission signal and the reception signal using M cancels the acoustic echo caused by the reception sound output from the speaker 8 being input to the microphone 2.

The receiving state detecting circuit 9 (receiving state detecting means in the present invention) includes a transmitting signal level output from the echo canceller 4 and input to the transmitting electronic volume 5 and an echo signal output from the receiving amplifier 6. By comparing the level of the reception signal input to the canceller 4 with the reception state, whether or not the reception state is detected is detected. When the reception state is detected, the reception state notification indicating the reception state is transmitted to the echo suppression control. It outputs to the circuit 10 (control means in the present invention).

The volume switch 11 (reception volume setting means in the present invention) can mechanically set the volume of the reception sound in response to the user operating the up switch 11a or the down switch 11b. And the up switch 11a or the down switch 11b
Is operated, a volume setting command indicating a set value set according to the operation is output to the echo suppression control circuit 10.

When a volume setting command is input from the volume switch 11, the echo suppression control circuit 10
A volume control command is output to the receiving electronic volume 7 according to the input volume setting command. Then, the reception electronic volume 7 attenuates the level of the reception signal input from the echo canceller 4 according to the volume control command input from the echo suppression control circuit 10. With such a configuration, the user can adjust the volume of the reception sound output from the speaker 8 by operating the volume switch 11.

As shown in FIG. 2, the echo suppression control circuit 10 includes a set value (volume set value) at the volume switch 11 and an attenuation of the level of the transmission signal in the transmission electronic volume 5 (echo suppression attenuation). ) Is held, and when a volume setting command is input from the volume switch 11,
An echo suppression attenuation amount corresponding to the volume setting value indicated by the input volume setting instruction is read, and an echo suppression control instruction indicating the read echo suppression attenuation amount is output to the transmission electronic volume 5.

The transmission electronic volume 5 attenuates the level of the transmission signal input from the echo canceller 4 in accordance with the echo suppression control command input from the echo suppression control circuit 10.

In this case, the echo suppression control circuit 1
0 indicates that the volume setting value of the volume switch 11 is set to five levels from "1" to "5". When the volume setting value of the volume switch 11 is relatively large, the attenuation level of the transmission signal level is compared. The value of the echo suppression attenuation is set to a relatively large value so as to achieve a large value. On the other hand, when the volume setting value of the volume switch 11 is relatively small, the attenuation of the level of the transmission signal is relatively small. Thus, the value of the echo suppression attenuation is set to a relatively small value.

When the volume setting value of the volume switch 11 is "2" or less (a predetermined level or less in the present invention), the echo suppression control circuit 10 sets the value of the attenuation of the level of the transmission signal to the value. "0.0dB"
By setting as, the level of the transmission signal is not attenuated, that is, the echo suppression function is stopped. Further, the echo suppression control circuit 10 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 a volume setting command from the volume switch 11, the echo suppression control circuit 10 determines the volume setting value indicated by the input volume setting command (Step S).
1).

Here, the echo suppression control circuit 10
If the volume setting value is equal to or less than the value at which the echo suppression function should be activated, specifically, if the volume setting value is equal to or less than “2”, “NO” is determined in step S2, and the process returns to step S1 described above. The volume setting value 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, specifically, if the volume setting value exceeds "2", the echo suppression control circuit 10 proceeds to step S2. "YE
S ", and determines whether or not the receiving state notification has been input from the receiving state detecting circuit 9 to determine whether or not the receiving state is established (step S3).

Here, the echo suppression control circuit 10
If the receiving state notification is not input from the receiving state detecting circuit 9 and the receiving state is not the receiving state, “N” is determined in step S3.
O ", the process returns to step S1, and the volume set value is determined again.

On the other hand, the echo suppression control circuit 10 has received the reception state notification from the reception state detection circuit 9, and if it is in the reception state, it determines "YES" in step S3, and determines the volume setting value and the echo With reference to a table corresponding to the suppression attenuation amount (step S4),
The echo suppression attenuation is determined according to the volume setting value indicated by the input volume setting command (step S
5).

The echo suppression control circuit 10
By outputting an echo suppression control command to the transmission electronic volume 5, the level of the transmission signal is attenuated in accordance with the determined echo suppression attenuation amount (step S6), and the process returns to step S1 described above. The same processing as described above is repeatedly 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. Further, the value of the echo suppression attenuation amount with respect to the volume setting 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, in the echo suppression control circuit 10, the speaker 8
When it is determined that the volume of the received sound output from is relatively large, the level of the transmitted signal is attenuated in a state where the level of the transmitted signal is attenuated relatively large. In contrast, even when the volume of the received sound is relatively large, the level of the transmission signal is relatively attenuated, so that the acoustic echo can be sufficiently canceled. When it is determined that the volume of the received sound to be received is relatively low, the level of the transmission signal is attenuated with the level of attenuation of the transmission signal relatively low, so that it differs from the conventional one. Therefore, since the amount of attenuation of the transmission signal level is relatively small, even when the volume of the received sound is relatively small,
Deterioration of the sense of discontinuity of sound can be avoided beforehand, thereby improving usability.

When the echo suppression control circuit 10 determines that the volume of the reception sound output from the speaker 8 is equal to or lower than a predetermined level, specifically, the volume setting value is equal to or lower than "2", the transmission signal is transmitted. The echo suppression function is stopped by setting the amount of attenuation of the level as "0.0 dB". Therefore, in the case where the volume of the received sound is extremely low, only the echo canceller function is operated. In a case where the acoustic echo can be sufficiently canceled, it is possible to prevent the unnecessary operation of the echo suppress function.

Further, since the echo suppression control circuit 10 is configured to determine the volume of the received sound output from the speaker 8 by determining the volume set value mechanically set by the volume switch 11,
The volume of the received sound can be determined with a relatively simple configuration.

In the receiving state detecting circuit 9, the level of the receiving signal output from the receiving amplifier 6 and input to the echo canceller 4 and the level of the transmitting signal output from the echo canceller 4 and input to the transmitting electronic volume 5 are shown. By comparing the level with the level, it is configured to detect whether or not the receiver is in the receiving state. Can be detected.

Further, since the echo suppression control circuit 10 is configured to be able to freely change the value of the echo suppression attenuation with respect to the volume set value, the echo suppression attenuation can be set to an optimum value according to the form of the system, for example. Can be set flexibly, and the usage pattern can be expanded.

(Second Embodiment) Next, a second 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 10
Is configured to determine the volume of the reception sound output from the speaker 8 by inputting a volume setting command from the volume switch 11 and determining only the volume setting value mechanically set by the volume switch 11. On the other hand, in the second embodiment,
The volume of the received sound is estimated and calculated based on the relationship between the volume set value mechanically set by the volume switch 11 and the level of the received signal, and the calculation result is determined, thereby determining the volume of the received sound. It is configured as follows.

More specifically, in the voice communication device 21, the receiving volume calculating circuit 22 (receiving volume calculating means in the present invention) receives a volume setting command from the volume switch 11, By integrating the signal level, the volume of the received sound is determined based on the relationship between the volume set value indicated by the volume setting command input from the volume switch 11 and the integration result obtained by integrating the level of the received signal input from the echo cancel 4. Is estimated and calculated, and a speaker output level notification indicating the calculation result is output to the echo suppression control circuit 23 (control means in the present invention).

As shown in FIG. 5, the echo suppression control circuit 23 outputs the output level of the speaker 8 (speaker output level), the attenuation of the transmission signal level in the transmission electronic volume 5 (echo suppression attenuation). When a speaker output level notification is input from the receiving sound volume calculation circuit 22, an echo suppression attenuation amount corresponding to the speaker output level indicated by the input speaker output level notification is read, and the read echo suppressor is output. An echo suppression control command indicating the amount of attenuation is output to the transmission electronic volume 5.

The transmission electronic volume 5 adjusts the level of the transmission signal input from the echo canceller 4 in the same manner as in the first embodiment described above.
It attenuates according to the echo suppression control command input from 0.

When a volume setting command is input from the volume switch 11, the reception volume calculation circuit 22 outputs a volume control command to the reception electronic volume 24 in accordance with 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 can adjust the volume of the reception sound output from the speaker 8 by operating the volume switch 11 in the same manner as in the first embodiment.

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 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 S11).

Here, the echo suppression control circuit 23
If the speaker output level is equal to or less than the value at which the echo suppression function should be activated, specifically, if the speaker output level is equal to or less than “150 dBm”, “NO” is determined in step S12, and the process returns to step S11.
The speaker output level is determined again.

On the other hand, if the loudspeaker output level exceeds the value at which the echo suppress function is to be activated, specifically, if the loudspeaker output level exceeds "150 dBm", the echo suppressor control circuit 23 proceeds to step S12. 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 S13).

Here, the echo suppress control circuit 23
If the receiving state notification is not input from the receiving state detecting circuit 9 and the receiving state is not the receiving state, "N" is determined in step S13.
O "and returns to step S11 described above.
Determine the speaker output level.

On the other hand, the echo suppression control circuit 23 has received the receiving state notification from the receiving state detecting circuit 9 and, if the receiving state is in the receiving state, determines "YES" in step S13, and determines the speaker output level and the echo With reference to a table corresponding to the suppression attenuation amount (step S1)
4) The echo suppression attenuation is determined according to the speaker output level indicated by the input speaker output level notification (step S15).

Then, the echo suppress control circuit 23
By outputting the echo suppression control command to the transmission electronic volume 5, the level of the transmission signal is attenuated according to the determined echo suppression attenuation amount (step S16).
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 second embodiment, the same functions and effects as those of the first embodiment can be obtained. In particular, in this case, the received sound volume calculation circuit 22 estimates and calculates the volume of the received sound based on the relationship between the volume set value mechanically set by the volume switch 11 and the level of the received signal. Since the sound volume of the reception sound output from the speaker 8 is determined by determining the calculation result in the echo suppression control circuit 10, the comparison of the reception sound with the one described in the first embodiment described above. In determining the volume, the accuracy can be improved.

(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. 1 showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a speaker output level and an echo suppression attenuation amount.

FIG. 6 is a diagram corresponding to FIG. 3;

[Explanation of symbols]

In the drawings, 1 is a voice communication device, 2 is a microphone (transmission sound input means), 4 is an echo canceller, 5 is a transmission electronic volume (transmission signal attenuation means), 8 is a speaker (reception sound output means), 9 Is a reception state detection circuit (reception state detection means), 10 is an echo suppression control circuit (control means), 1
1 is a volume switch (received sound volume setting means), 21 is a voice communication device, 22 is a received sound volume calculation circuit (received sound volume calculation means), and 23 is an echo suppression control circuit (control means).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D020 CC01 5K027 BB03 DD08 DD10 DD11 DD14 DD16 HH03 5K046 HH13 HH44 HH79

Claims (6)

[Claims] 1. A voice communication device configured to realize hands-free communication, a receiving sound output means for receiving a receiving signal and outputting a receiving sound, and receiving a transmitting sound and outputting a transmitting signal. A transmission sound input unit, an echo canceller that cancels an acoustic echo caused by a reception sound output from the reception sound output unit being input to the transmission sound input unit, and an output from the transmission sound input unit. Transmitting signal attenuating means for attenuating the level of the transmitted transmitting signal; receiving state detecting means for detecting whether or not the receiving state; and the receiving state detecting means detecting that the receiving state is being received. Control means for operating the transmission signal attenuating means, wherein the control means determines that the volume of the reception sound output from the reception sound output means is relatively high, When the transmission signal attenuating means is operated in a state where the attenuation of the level of the transmission signal in the signal attenuating means is relatively large, and it is determined that the volume of the received sound output from the received sound output means is relatively small. A voice communication device for operating the transmission signal attenuating means in a state where the amount of attenuation of the level of the transmission signal in the transmission signal attenuating means is relatively small. 2. The method according to claim 1, wherein the control unit stops the operation of the transmission signal attenuating unit when the control unit determines that the volume of the reception sound output from the reception sound output unit is equal to or lower than a predetermined level. The voice communication device according to claim 1. 3. A receiving sound volume setting means capable of mechanically setting a receiving sound volume, wherein the control means determines a set value in the receiving sound volume setting means and outputs the received sound from the receiving sound output means. 2. The volume of a received sound to be received is determined.
Or the voice communication device according to 2. 4. A receiving sound volume setting means capable of mechanically setting a receiving sound volume, and an output from the receiving sound output means based on a relationship between a set value in the receiving sound volume setting means and a level of the receiving signal. Receiving sound volume calculation means for estimating and calculating the volume of the received sound to be received, wherein the control means determines a result of the calculation by the received sound volume calculating means, thereby obtaining a received sound output from the received sound output means. The voice communication device according to claim 1, wherein the volume is determined. 5. The apparatus according to claim 1, wherein the receiving state detecting unit detects whether the apparatus is in a receiving state by comparing a level of the receiving signal with a level of the transmitting signal. 5. The voice communication device according to any one of 4. 6. The voice communication apparatus according to claim 1, wherein said control means is capable of changing an amount of attenuation of a transmission signal level in said transmission signal attenuating means.