JP2001268212A - Voice communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice communication device that can fully cancel a voice echo and avoid deterioration due to an intermittent sense of voice in advance, even when a portable telephone of any communication system is connected to the device. SOLUTION: An echo suppress control circuit 11 discriminates whether the portable telephone 2 connected to the voice communication device adopts a communication system of a personal digital cellular(PDC) system or a code division multiple access(CDMA) system, by discriminating a discrimination result notice outputted using a communication system discrimination circuit 13, sets attenuation of the level of a transmission signal depending on the commutation system adopted by the connected telephone 2 to attenuate a level of a transmission signal. Thus, even when either of the telephone adopting the PDC system and the telephone adopting the CDMA system is connected to the unit, the unit can bring the attenuation of the level of the transmission signal to a proper level, resulting that voice echo can be fully cancelled and the deterioration in the intermittent sense of voice can be avoided in advance.

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 be connectable to a portable telephone and 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, in recent years, a personal digital cellular (PDC) system and a code division multiple access (CDMA) system have been developed.
le Access) and other mobile phones with different communication systems have been put into practical use, and accordingly, the above-described voice communication device has a configuration that can be connected to any of the mobile phones with different communication systems. It is common.

However, the level of the transmission signal is attenuated differently between communication networks of different communication systems, so that the attenuation of the level of the transmission signal in the voice communication apparatus is reduced as described above. Is constant, when a mobile phone adopting one communication method is connected to the voice communication device and the level of attenuation of the transmission signal is an optimal value, the mobile phone adopting another communication method Was connected to the voice communication device, the level of attenuation of the transmission signal deviated from the optimum value. And as a result, it is not possible to cancel the acoustic echo sufficiently,
In addition, there is a problem that a sense of interruption of voice is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to sufficiently cancel an acoustic echo even when any of mobile phones having different communication systems is connected. And it is possible to prevent deterioration of the sense of discontinuity of the sound beforehand,
An object of the present invention is to provide a voice communication device capable of 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. The communication method determining means determines the communication method of the connected mobile phone, and the control means controls the communication method of the communication method determining means on condition that the receiving state detecting means detects the receiving state. The level of the level of the transmission signal in the transmission signal attenuating means is set in accordance with the result of the determination, and the transmission signal attenuating means is operated. Attenuate signal levels.

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 communication system of the connected portable telephone. In contrast to the case of connecting a mobile phone adopting one communication method and a mobile phone adopting another communication method, the attenuation of the level of the transmission signal is optimized. Value, so that acoustic echo can be sufficiently canceled,
In addition, it is possible to prevent deterioration of the sense of discontinuity of sound beforehand. Thereby, usability can be improved.

According to the second aspect of the present invention, the control means determines that the communication system of the connected portable telephone is a communication system in which the level of the level of the transmission signal in the communication network is relatively large. When the communication method determining means determines, the attenuation of the level of the transmission signal in the transmission signal attenuating means is set to a relatively small value, the transmission signal attenuating means is operated, and the communication method of the connected mobile phone is set to the communication mode. When the communication system determining means determines that the communication system has a relatively small amount of attenuation of the level of the transmission signal in the network, the attenuation of the level of the transmission signal in the transmission signal attenuation unit is set to a relatively large amount. Activate the transmission signal attenuating means.

That is, according to this, when a portable telephone of a communication system in which the level of the transmission signal level is relatively attenuated in the communication network is connected, the level of the transmission signal is attenuated relatively small. Set to attenuate the level of the transmission signal, and conversely, when connected to a communication-type mobile phone in which the level of the transmission signal level in the communication network is relatively small, the transmission signal is attenuated. Is configured to attenuate the level of the transmission signal by setting the attenuation of the level of the transmission signal to a relatively large value, so that regardless of the attenuation of the level of the transmission signal in the communication network, any mobile phone is connected. Even if there is, it is possible to sufficiently cancel the acoustic echo, and it is possible to avoid the deterioration of the sense of discontinuity of the sound.

According to the third aspect of the present invention, when the communication system determining unit determines that the communication system of the connected mobile phone is the personal digital cellular system, the control unit controls the transmission signal attenuation. The transmission signal attenuating means is operated by setting the amount of attenuation of the transmission signal level in the means to be relatively small, and the communication method determining means determines that the communication method of the connected mobile phone is the code division multiple access method. When it is determined, the attenuation of the level of the transmission signal in the transmission signal attenuating means is set relatively large, and the transmission signal attenuating means is operated.

That is, according to this, when a personal digital cellular type mobile phone is connected, the level of the transmission signal is attenuated by setting the level of attenuation of the level of the transmission signal to be relatively small. When a mobile phone of a code division multiple access system is connected, the level of the transmission signal is attenuated by setting the level of attenuation of the transmission signal to be relatively large. Since the level of transmission signal attenuation in a digital cellular communication network is relatively large, and the level of transmission signal attenuation in a code division multiple access communication network is relatively small, the personal digital cellular system is used. Acoustic echo is sufficiently canceled regardless of whether the mobile phone is connected to a mobile phone or a code-division multiple access mobile phone. Rukoto can, also, it is possible to avoid in advance the deterioration of the sense of interruption of voice.

According to the fourth 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.

That is, according to this configuration, when it is determined that the volume of the reception sound is lower than the predetermined level, the operation of the transmission signal attenuating means is stopped, so that the volume of the reception 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 fifth 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.

That is, according to this, the level of attenuation of the transmission signal in the transmission signal attenuating means is configured to be variable, so that the level of attenuation of the transmission signal is optimized according to the form of the system, for example. 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.

According to the voice communication apparatus of the sixth aspect, the communication method determining means transmits the non-telephone service request command to the connected mobile telephone, and confirms the non-telephone service transmitted by the connected mobile telephone. By receiving the command, the communication system of the connected mobile phone is determined.

That is, according to this, a non-telephone service request command is transmitted to the connected portable telephone,
Since the communication method of the connected mobile phone is determined by receiving the non-telephone service confirmation command transmitted by the connected mobile phone, the non-telephone service request command and the non- By using the telephone service confirmation command, it is possible to easily determine the communication method of the connected mobile phone without using a new command.

[0021]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a functional block diagram showing a portion according to the gist of the present invention. The voice communication device 1 is configured to be connectable to a mobile phone 2. First, in the voice communication device 1, the transmission system will be described.
(Transmission sound input means according to the present invention) receives a voice uttered by the user as a transmission sound, generates a transmission signal by processing the input transmission sound, and transmits the generated transmission signal. Output to the talk amplifier 4.

When a transmission signal is input from the microphone 3, the transmission amplifier 4 amplifies the input transmission signal and outputs the amplified transmission signal to the echo canceller 5. When the transmission signal is input from the transmission amplifier 4, the echo canceller 5 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 6 (the present invention). (Transmission signal attenuating means).

When a transmission signal is input from the echo canceller 5, the transmission electronic volume 6 attenuates the level of the input transmission signal and transmits the level-attenuated transmission signal to the portable telephone as described later in detail. The signal is output to a wireless circuit (not shown) of the telephone 2. Then, when the wireless circuit of the mobile phone 2 receives the transmission signal from the transmission electronic volume 6,
Wirelessly process the input transmission signal.

Next, the reception system will be described. The reception amplifier 7 receives a reception signal from the wireless circuit of the mobile phone 2 and amplifies the input reception signal, and outputs the amplified reception signal to the echo canceller 5. When the echo canceller 5 receives the reception signal from the reception amplifier 7, the echo cancellation processing is performed on the input reception signal in relation to the transmission signal, and the reception signal subjected to the echo cancellation processing is output to the reception electronic volume 8.

When the reception electronic volume 8 receives a reception signal from the echo canceller 5, the level of the received reception signal is attenuated, and the received reception signal whose level is attenuated is transmitted to a speaker 9 (referred to in the present invention), as will be described later in detail. Receiving sound output means). Then, upon receiving the reception signal from the reception electronic volume 8, the speaker 9 performs voice processing on the input reception signal to generate a reception sound, and outputs the generated reception sound.

In the above configuration, the echo canceller 5 includes an adaptive filter, an adder, a ROM, and the like.
The echo cancellation processing is performed on the transmission signal and the reception signal using M to cancel the acoustic echo caused by the reception sound output from the speaker 9 being input to the microphone 3.

The receiving state detecting circuit 10 (receiving state detecting means in the present invention) detects the level of the transmitting signal output from the echo canceller 5 and input to the transmitting electronic volume 6,
By comparing the level of the reception signal output from the reception amplifier 7 and input to the echo canceller 5, 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 11 (control means in the present invention).

The volume switch 12 (receiving volume setting means in the present invention) can mechanically set the volume of the receiving sound in response to the user operating the up switch 12a or the down switch 12b. And 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 echo suppression control circuit 11.

The communication system discrimination circuit 13 (communication system discrimination means in the present invention) transmits a non-telephone service request command to the mobile phone 2 and receives a non-telephone service confirmation command from the mobile phone 2 in response to the command. Thus, the mobile phone 2 connected to the voice communication device 1 determines which communication system is used, and outputs a determination result notification indicating the determination result to the echo suppression control circuit 11. In this case, specifically, the communication method determination circuit 13
Means that the mobile phone 2 is a personal digital cellular (PD)
C: Personal Digital Cellular (CDMA) type mobile phone or code division multiple access (CDMA: Co
It is determined whether or not the mobile phone adopts the de Division Multiple Access (Deletion Multiple Access) method.

When the echo suppression control circuit 11 inputs a volume setting command from the volume switch 12, the echo suppression control circuit 11
A volume control command is output to the receiving electronic volume 8 according to the input volume setting command. Then, the reception electronic volume 8 attenuates the level of the reception signal input from the echo canceller 5 in accordance with the volume control command input from the echo suppression control circuit 11. With such a configuration, the user can adjust the volume of the reception sound output from the speaker 9 by operating the volume switch 12.

As shown in FIG. 2, the echo suppression control circuit 11 includes a set value (volume set value) at the volume switch 12 and an attenuation amount of the transmission signal level (echo suppression attenuation) at the transmission electronic volume 6. And a table corresponding to the amount. here,
The echo suppression control circuit 11 includes, as an echo suppression attenuation amount, an echo suppression attenuation amount when a mobile phone employing a personal digital cellular system is connected, and an echo suppression attenuation when a mobile phone employing a code division multiple access system is connected. The amount of attenuation is set to be different from the amount of attenuation.

The echo suppression control circuit 11
When a volume setting command is input from the volume switch 12, the corresponding echo suppression attenuation is read in response to the input volume setting command and the notification of the determination result input from the communication method determination circuit 13, and indicates the read echo suppression attenuation. An echo suppression control command is output to the transmission electronic volume 6. Then, the transmission electronic volume 6 attenuates the level of the transmission signal input from the echo canceller 5 according to the echo suppression control command input from the echo suppression control circuit 11.

In this case, the echo suppression control circuit 1
1 sets the volume setting value of the volume switch 12 in five steps from "1" to "5", and when the volume setting value of the volume switch 12 is "3" or more, the personal digital cellular system is adopted. The value of the echo suppression attenuation when the mobile phone is connected is set to a constant value of "-6.0 dB", and the echo suppression attenuation when the mobile phone adopting the code division multiple access system is connected. The value is set constant as "-12.0 dB".

When the volume setting value of the volume switch 12 is equal to or less than "2" (the predetermined level or less in the present invention), the echo suppression control circuit 11 sets the echo suppression attenuation value to "0.0 dB". By setting, the level of the transmission signal is not attenuated, that is, the echo suppression function is stopped. Further, the echo suppression control circuit 11 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 determination result notification from the communication method determination circuit 13, the echo suppression control circuit 11 determines the communication method of the mobile phone 2 indicated by the input determination result notification (step S1). When receiving a volume setting command from the volume switch 12, the echo suppression control circuit 11 determines the volume setting value indicated by the input volume setting command (step S2).

Here, the echo suppression control circuit 11
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 S3, and the process returns to step S2. 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 is equal to or more than "3", the echo suppression control circuit 11 proceeds to step S3. YES "
It is determined whether or not the receiver is in the receiving state by determining whether or not the receiving state notification is input from the receiving state detecting circuit 10 (step S4).

Here, the echo suppression control circuit 11
If the receiving state notification is not input from the receiving state detecting circuit 10 and the receiving state is not the receiving state, "N" is determined in step S4.
O ", the process returns to step S2, and the volume setting value is determined again.

On the other hand, the echo suppression control circuit 11 receives the reception state notification from the reception state detection circuit 10,
If it is in the receiving state, "YES" is determined in the step S4, and the table in which the volume setting value and the echo suppression attenuation amount are associated with each other is referred to (step S4).
5) The echo suppression attenuation is determined according to the volume setting value indicated by the input volume setting command and the communication method indicated by the input discrimination result notification (step S6).

The echo suppression control circuit 11
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 S7), and the process returns to step S2. 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.

The value of the echo suppression attenuation 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, the echo suppression control circuit 11 determines the notification of the determination result output from the communication mode determination circuit 13 so that the communication of the connected cellular phone 2 can be performed. It is determined whether the system is the personal digital cellular system or the code division multiple access system, and the level of the transmission signal is attenuated according to the communication system of the connected mobile phone 2 to set the transmission signal. Is configured to attenuate the level of the mobile phone, which is different from the conventional one, when connecting either a mobile phone employing the personal digital cellular system or a mobile phone employing the code division multiple access system. Also, the attenuation of the level of the transmission signal can be set to an optimum value. As a result, acoustic echo can be sufficiently canceled, and A broken sense of deterioration can be avoided in advance. Thereby, usability can be improved.

When the echo suppression control circuit 11 determines that the volume of the received sound output from the speaker 9 is equal to or lower than a predetermined level, specifically, the volume setting value is equal to or lower than "2", the transmission is performed. 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 11 is configured so that the volume set value and the value of the echo suppression attenuation amount for the communication system of the portable telephone can be freely changed, the echo suppression control circuit 11 can control the echo suppression according to the form of the system, for example. 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.

Further, the echo suppress control circuit 11 transmits a non-telephone service request command to the connected mobile telephone 2 and receives the non-telephone service confirmation command transmitted by the connected mobile telephone 2,
Since the communication method of the connected mobile phone 2 is configured to be determined, by using the existing commands, ie, the non-telephone service request command and the non-telephone service confirmation command, without using a new command, The communication method of the connected mobile phone 2 can be easily determined.

(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 11 sets the echo suppression attenuation value to "-6.0 dB" or "-6.0". 12.0
dB ", the volume switch 12 is set to be constant.
When the volume set value of the volume switch 12 is equal to or more than “3”, when the volume set value of the volume switch 12 is relatively large, the values of the echo suppression attenuation are compared so that the attenuation of the level of the transmission signal becomes relatively large. On the other hand, when the volume setting value of the volume switch 12 is relatively small, the value of the echo suppression attenuation is set to be relatively small so that the attenuation of the level of the transmission signal is relatively small. It is set to the value.

More specifically, when the volume setting value of the volume switch 12 is "3", the echo suppression control circuit 11 determines the amount of echo suppression attenuation when a portable telephone employing the personal digital cellular system is connected. The value is set as “−3.0 dB”, while the value of the echo suppression attenuation when a mobile phone adopting the code division multiple access method is connected is set as “−6.0 dB”.

When the volume setting value of the volume switch 12 is "4", the echo suppress control circuit 11 sets the value of the echo suppress attenuation when a portable telephone employing the personal digital cellular system is connected to "-". 4.5 dB. On the other hand, the value of the echo suppression attenuation when a mobile phone adopting the code division multiple access system is connected is set to "-9.0 dB".

Further, the echo suppression control circuit 11
When the volume setting value of the volume switch 12 is “5”, the value of the echo suppression attenuation when a mobile phone adopting the personal digital cellular system is connected is set to “−6.0 dB”. The value of the echo suppression attenuation when a mobile phone adopting the code division multiple access system is connected 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 11 receives a volume setting command from the volume switch 12 and determines only the volume setting value mechanically set by the volume switch 12. 9 is configured to determine the volume of the received sound output from
In the 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 12 and the level of the received signal, and the calculation result is determined, thereby determining the received sound. It is configured to determine the volume.

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 canceller 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 output of the indicated 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, as in the case of the echo suppression control circuit 11 described in the above-described first embodiment, sets the echo suppression attenuation amount as an echo in the case where a mobile telephone employing a personal digital cellular system is connected. The amount of suppression attenuation and the amount of echo suppression attenuation when a mobile phone adopting the code division multiple access system is connected are set to be different from each other.

Then, the echo suppress control circuit 23
When the speaker output level notification is input from the receiving sound volume calculation circuit 22, the corresponding echo suppression attenuation is read out according to the input speaker output level notification and the determination result notification input from the communication method determination circuit 13, and the read echo suppressor is read. An echo suppression control command indicating the amount of attenuation is output to the transmission electronic volume 6. Transmission electronic volume 6
Attenuates the level of the transmission signal input from the echo canceller 5 in accordance with 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.

When the volume setting command is input from the volume switch 12, the reception volume calculation circuit 22
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 9.

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 notification of the determination result from the communication method determination circuit 13, the echo suppression control circuit 23 determines the communication method of the mobile phone 2 indicated by the input notification of the determination result (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 suppress control circuit 23
If the speaker output level is equal to or less than the value at which the echo suppression function is to 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 S12 described above.
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 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 10 and the receiving state is not the receiving state, "N" is determined in step S14.
O "and returns to step S12 described above.
Determine the speaker output level.

On the other hand, the echo suppression control circuit 23 receives the reception state notification from the reception state detection circuit 10 and
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 in accordance with the speaker output level indicated by the input speaker output level notification and the communication scheme indicated by the input discrimination 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 S12, and thereafter, the same processing is repeated and executed.

Also in this case, the value of the echo suppression attenuation 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 functions and effects as those of the first embodiment can be obtained. In this case, in particular, in this case, the volume switch 12 The volume of the received sound is estimated and calculated based on the relationship between the volume set value mechanically set and the level of the received signal, and the result of calculation 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 described above, the echo suppression control circuit 23 sets the value of the echo suppression attenuation to "-6.0 dB" when the speaker output level in the reception volume calculation circuit 22 exceeds "150 dBm". Alternatively, it is set to a fixed value of "-12.0 dB". On the other hand, in the fourth embodiment, the speaker output level in the receiving sound volume calculation circuit 22 is set to "150 dB".
Bm ", the value of the echo suppression attenuation is set to a relatively large value so that when the speaker output level is relatively large, the attenuation of the transmission signal level is relatively large, On the other hand, when the speaker output level is relatively low, 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.

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 mobile phone, 3 is a microphone (transmitting sound input means), 5 is an echo canceller,
6 is a transmission electronic volume (transmission signal attenuation means), 9 is a speaker (reception sound output means), 10 is a reception state detection circuit (reception state detection means), 11 is an echo suppression control circuit (control means), 13 is A communication method discrimination circuit (communication method discrimination means), 21 is a voice communication device, and 23 is an echo suppression control circuit (control means).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K027 AA11 BB03 DD10 DD14 DD16 FF22 FF29 HH03 MM04 MM17 5K046 AA05 BA05 BB01 HH11 HH13 HH61 HH69 HH79

Claims (6)

[Claims] 1. A receiving sound output means for receiving a receiving signal and outputting a receiving sound, and receiving a transmitting sound. A transmission sound input unit that outputs a transmission signal by performing the above operation; and 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. Transmission signal attenuating means for attenuating the level of the transmission signal output from the transmission sound input means; receiving state detecting means for detecting whether or not the apparatus is in a receiving state; and detecting the receiving state in the receiving state. And a control means for operating the transmission signal attenuating means on condition that the communication means detects the communication method. Wherein the control means sets the attenuation of the level of the transmission signal in the transmission signal attenuating means in accordance with the result of the determination by the communication method determining means, and operates the transmission signal attenuating means. Voice communication device. 2. The control means according to claim 1, wherein said communication method discriminating means determines that the communication method of the connected mobile phone is a communication method in which the level of the transmission signal level in the communication network is relatively large. The level of attenuation of the transmission signal level in the transmission signal attenuating means is set to a relatively small value to operate the transmission signal attenuating means, and the communication system of the mobile telephone connected to the transmission signal attenuates the transmission signal in the communication network. When the communication method discriminating means determines that the communication method has a relatively small level attenuation, the attenuation of the level of the transmission signal in the transmission signal attenuating means is set to be relatively large, and the transmission signal 2. The voice communication device according to claim 1, wherein the attenuator is operated. 3. The control means according to claim 1, wherein said communication method determination means determines that the communication method of the connected mobile phone is a personal digital cellular method, and the level of the transmission signal in said transmission signal attenuation means is determined. When the communication system determining unit determines that the communication system of the connected mobile phone is a code division multiple access system, the communication system determining unit determines that the transmission signal attenuating unit is operated by setting the attenuation amount of the transmission signal to a relatively small amount. 3. The voice communication device according to claim 1, wherein the transmission signal attenuating means is operated by setting the amount of attenuation of the level of the transmission signal in the transmission signal attenuating means to be relatively large. 4. When the control means determines that the volume of the received sound output from the received sound output means is lower than a predetermined level, the control means stops the operation of the transmission signal attenuating means. The voice communication device according to claim 1. 5. The voice communication apparatus according to claim 1, wherein said control means is capable of changing an amount of attenuation of a level of a transmission signal in said transmission signal attenuating means. 6. The connection method by transmitting a non-telephone service request command to a connected mobile phone and receiving a non-telephone service confirmation command transmitted by the connected mobile phone. The voice communication device according to any one of claims 1 to 5, wherein the communication system of the mobile phone is determined.