JP2001119470A - Telephone voice processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a telephone voice processor that can properly conduct voice processing in a hands-free telephone set and effectively conduct echo elimination processing or the like. SOLUTION: In a telephone voice processor that is used for a hands-free telephone set which transmits a voice picked up by a microphone 10 installed in the interior of a vehicle and reproduces the voice of the destination from a speaker 11 installed in the interior of the vehicle and that synthesizes an echo cancelation signal obtained by applying delay processing to a received signal of a phone 1 and adjusting the level with an input signal to the microphone 10 to generate a transmission signal so as to eliminate an echo mixed to the transmission signal resulting from the received speech signal reproduced from the speaker 11 and given to the microphone 10, an operating condition of a voice processing section that processes a transmission voice signal and a reception voice signal is set properly in response to conditions such as a transmission sound volume, a reception sound volume and a model of the vehicle or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone voice used in a hands-free telephone and for processing a voice signal such as preventing an echo transmitted from a speaker to be picked up by a microphone and transmitted to the other party. It relates to a processing device.

[0002]

2. Description of the Related Art Mobile phones have become widespread and have been used in automobiles. However, it is necessary to operate the steering wheel or the like while driving a car, so that it is difficult to use a telephone. Forcing the use of the telephone will adversely affect safety. For this reason, the ban on the use of mobile phones while driving is being legislated.

[0003] Under such circumstances, particularly as a vehicle-mounted telephone, a hands-free telephone that does not require the use of a hand even while driving a car and is easy to secure safety is rapidly spreading. Hands-free telephones input voice into a microphone installed in the cabin, transmit this voice to the other party,
It reproduces the voice from the other party through a speaker installed in the vehicle interior, and makes it possible to talk during driving even if it is not necessary to hold a handset.

[0004]

However, in a hands-free telephone, it is difficult to hear the sound at the other party because the received sound reproduced from the speaker is picked up by the microphone and the received signal is mixed with the transmitted signal. In some cases, an echo problem occurs in which the signal leaks from a transmission circuit, a reception circuit, or the like, is reflected in the received sound of the own telephone, and it becomes difficult to hear the received sound. For this reason, it is possible to apply delay and level adjustment processing to the received signal to generate an inverted phase signal of the received signal picked up by the microphone and to perform echo removal processing or the like for removing the received signal picked up by the microphone. Many.

However, since the delay characteristics and level adjustment characteristics in the echo removal processing are average values determined at the time of design, there is a problem that the effect is small depending on the type of vehicle. Also, when the voice volume of the other party or the voice volume of the own side is large, the A / D conversion value overflows beyond the maximum conversion input of the analog-to-digital (A / D) converter, and conversely, If the voice volume of the other party or the voice volume of the self side is small, the accuracy of A / D conversion is reduced, and as a result, there is a problem that voice processing such as echo removal processing may not be performed well.

An object of the present invention is to solve such a problem, and an object of the present invention is to realize a telephone voice processing apparatus capable of appropriately performing voice processing in a hands-free telephone and effectively performing echo removal processing and the like.

[0007]

Means for Solving the Problems and Effects Therefor To solve the above problems, a telephone voice processing apparatus (1) according to the present invention.
Is used for a hands-free telephone that transmits a voice input to a microphone installed in the vehicle interior to a destination and reproduces the voice of the destination from a speaker installed in the vehicle interior, and delays a reception signal of the telephone. The received speech signal reproduced from the speaker is input to the microphone by combining the echo cancellation signal obtained by performing the processing and level adjustment with the input signal of the microphone to form a transmission signal. In the telephone voice processing apparatus for removing echoes mixed in the transmitted signal by the voice processing, the voice volume detecting means for detecting the voice volume of the speaker, and the voice transmitting means according to the voice volume detected by the voice volume detecting means. And a transmission level adjusting means for adjusting the level of the speech signal.

According to the telephone voice processing device (1), a transmission signal whose voice level is adjusted in accordance with the volume of voice of the speaker is transmitted, so that the reproduction volume at the other party of the call is appropriately adjusted. Therefore, it is possible to prevent a situation in which the other party feels painful even when the generated volume is high, and conversely, the other party cannot grasp the content of the call even when the generated volume is low.

Further, in the telephone voice processing apparatus (2) according to the present invention, in the telephone voice processing apparatus (1), the utterance volume detecting means may output the voice of the speaker when the reception signal at the start of the call is in a silent state. It is characterized by detecting the volume. According to the telephone voice processing device (2), the speaker's utterance volume can be detected without being affected by the utterance voice of the other party, so that the speaker's utterance volume can be accurately detected.

A telephone voice processing device (3) according to the present invention transmits voice input to a microphone installed in a vehicle compartment to a destination, and transmits voice of the destination from a speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. In a telephone voice processing device for removing an echo mixed in a transmission signal when a voice signal is input to the microphone, a reception sound volume detection unit for detecting a reception volume corresponding to a volume of a voice of the other party from the reception signal. Receiving level adjusting means for adjusting the reproduction volume level of the received voice signal according to the receiving volume detected by the receiving volume detecting means.

According to the telephone voice processing device (3), the voice reproduction level is adjusted in accordance with the utterance volume of the other party, so that the reproduction volume from the speaker becomes appropriate, and the generation of the other party can be reduced. It is possible to prevent the occurrence of a situation where the volume is too loud and the ears are hurt, and conversely, the generated volume is so low that the contents of the call cannot be grasped.

Further, the telephone voice processing device (4) according to the present invention is characterized in that, in the telephone voice processing device (3), the reception volume detection means detects the reception volume at the start of a call. I have. According to the telephone voice processing device (4), the voice volume of the communication partner can be detected without being affected by the voice of the user, for example, the voice of the user returning around the handset of the communication partner. Therefore, it is possible to accurately detect the utterance volume of the other party.

Further, the telephone voice processing device (5) according to the present invention transmits voice input to a microphone installed in the vehicle interior to the other party, and transmits the voice of the other party from a speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. In a vehicle-mounted telephone voice processing device for removing an echo mixed in a transmission signal when a voice signal is input to the microphone, a vehicle type detecting means for detecting a vehicle type of the vehicle, and a vehicle type detected by the vehicle type detecting means Condition setting means for setting the conditions for generating the echo cancellation signal in accordance with the conditions.

According to the telephone speech processing device (5), an echo cancellation signal is generated in accordance with the delay time and the amount of attenuation from the source signal of the echo which varies according to the vehicle type. Also, effective echo removal according to the vehicle type can be performed.

Further, the telephone voice processing device (6) according to the present invention transmits the voice input to the microphone installed in the vehicle interior to the other party, and transmits the voice of the other party from the speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. An in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal when a voice signal is input to the microphone, wherein a frequency band of a vehicle noise generated as the vehicle travels from the input signal to the microphone. A vehicle noise filter that removes a signal, a vehicle noise level detection unit that detects a level of the vehicle noise, and a vehicle noise filter that is responsive to the vehicle noise level detected by the vehicle noise level detection unit. Operating condition setting means for setting operating conditions.

According to the telephone voice processing device (6), the vehicle noise is appropriately removed, that is, the noise removal amount is insufficient and the noise is conspicuous, or conversely, the noise removal amount is too large and the speech sound is reduced. Occurrence of an obscured situation can be minimized.

Further, the telephone voice processing device (7) according to the present invention transmits the voice input to the microphone installed in the vehicle interior to the other party, and transmits the voice of the other party from the speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. In an in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal when a voice signal is input to the microphone, the level of an output signal from the microphone is adjusted, and an output signal level to the speaker is adjusted. And a microphone output adjusting means for reducing the size of the microphone.

According to the telephone sound processing device (7), the level of the output signal from the microphone becomes smaller than the level of the output signal to the speaker, that is, the output signal from the microphone is processed without causing overflow or the like. Can be reliably controlled within the maximum input signal level (the output signal level to the speaker, which is the processed output, does not exceed the maximum input signal level), so distortion and noise due to excessive input can be reduced. Can be prevented.

Further, a telephone voice processing device (8) according to the present invention transmits a voice input to a microphone installed in a vehicle interior to a destination, and transmits the voice of the destination from a speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. An in-vehicle telephone voice processing device that removes echoes mixed in a transmission signal when a voice signal is input to the microphone is obtained by performing delay processing and level adjustment on the transmission signal of the telephone. The transmission echo canceling signal is combined with the reception signal, whereby transmission signal processing means for removing an echo generated by mixing the transmission signal with the reception signal, and an operation performed by an operator. Operation switching means for switching between operation and non-operation of the transmission signal processing means.

According to the telephone voice processing device (8), the user can select whether or not to perform processing for removing echo generated when a transmission signal mixes with a reception signal. When there is no need for processing on the telephone voice processing device side, such as when there is an echo removal function, there is no need to divide and use circuits such as memory for transmission echo cancellation processing. , And the received echo cancellation can be performed with high accuracy.

Further, the telephone voice processing device (9) according to the present invention transmits a voice input to a microphone installed in the vehicle interior to the other party, and transmits the voice of the other party from a speaker installed in the vehicle interior. Used for hands-free phones that play,
The reception signal reproduced from the speaker is formed by synthesizing the echo cancellation signal obtained by delaying the reception signal of the telephone and adjusting the level with the input signal of the microphone to form a transmission signal. An on-vehicle telephone voice processing device for removing an echo mixed into a transmission signal when a voice signal is input to the microphone, a one-way call detection means for detecting whether the call is a one-way call, An echo removal processing stopping means for stopping the echo removal processing when the one-way communication is detected by the call detection means.

According to the telephone voice processing device (9), useless echo cancellation is not performed when there is no utterance of itself, for example, in a one-way call such as a weather forecast or a time signal. Can be prevented from becoming unclear.

The telephone voice processing apparatus (1) according to the present invention
0) is used for a hands-free telephone that transmits voice input to a microphone installed in the vehicle interior to the other party and reproduces the voice of the other party from a speaker installed in the vehicle interior, and a reception signal of the telephone. The echo cancellation signal obtained by performing the delay processing and the level adjustment is combined with the input signal of the microphone to form a transmission signal, so that the reception voice signal reproduced from the speaker is converted to the microphone signal. An in-vehicle telephone voice processing device that removes echoes mixed in a transmission signal by being input to a telephone signal. An electric field intensity detection unit that detects an electric field intensity of a reception signal of the telephone, and the electric field intensity detection unit detects the electric field intensity of the reception signal. Transmission level adjusting means for adjusting the level of the transmission signal according to the electric field strength.

According to the telephone voice processing device (10),
Since the transmission signal level is adjusted according to the electric field strength of the telephone communication, it is possible to suppress the fluctuation of the reproduced voice on the communication partner side due to the fluctuation of the electric field strength.

The telephone voice processing apparatus (1) according to the present invention
1) is used for a hands-free telephone that transmits voice input to a microphone installed in the vehicle compartment to the other party and reproduces the voice of the other party from a speaker installed in the vehicle interior, and a reception signal of the telephone. The echo cancellation signal obtained by performing the delay processing and the level adjustment is combined with the input signal of the microphone to form a transmission signal, so that the reception voice signal reproduced from the speaker is converted to the microphone signal. An in-vehicle telephone voice processing device that removes echoes mixed in a transmission signal by being input to a telephone signal. An electric field intensity detection unit that detects an electric field intensity of a reception signal of the telephone, and the electric field intensity detection unit detects the electric field intensity of the reception signal. Receiving level adjusting means for adjusting the level of the receiving signal according to the electric field strength.

According to the telephone voice processing device (11),
Since the received signal level is adjusted according to the electric field strength of the telephone communication, it is possible to suppress the fluctuation of the reproduced sound due to the fluctuation of the electric field strength.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A telephone voice processing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of the telephone voice processing device according to the embodiment.

The telephone sound processing device 3 realizes an in-vehicle hands-free telephone system by connecting the portable telephone 1, and its main body is installed on an instrument panel in a vehicle compartment, a seat lower part, and the like. The microphone 10 acquires the voice of the speaker, and includes a driver such as a central portion of a steering wheel (not shown), a driver front portion of an instrument panel (not shown), a driver side pillar (not shown), and the like. It is installed in the part where it is easy to obtain the uttered voice of. The output signal of the microphone 10 is amplified by the microphone amplifier 9 and supplied to the audio processing unit 4.

The speaker 11 is a speaker for reproducing the voice of the other party, and may be a dedicated speaker.
Here, it is also used as a front speaker on the passenger seat side in the in-vehicle sound reproducing device. The voice signal of the other party is voice-processed in the voice processing unit 4, amplified by the power amplifier 8, and then output from the speaker 11 as voice.

The voice processing unit 4 processes a voice signal from the mobile phone 1 and outputs a voice signal to be reproduced to the speaker 11, and also processes a voice signal from the microphone 11 and outputs the processed voice signal to the mobile phone 1. , An analog-to-digital converter that converts an analog audio signal to a digital signal, a digital signal processor that performs digital arithmetic processing, and a digital-to-analog converter that converts a digital signal to an analog audio signal. .

A CPU (Central Processing Unit) 5 controls the operation of the audio processing unit 4 and communicates data signals other than the audio signal by the mobile phone 1. The CPU 5 controls programs and the operation of the audio processing unit 4. ROM where data is stored,
A memory 7 composed of a RAM for temporarily storing data in the middle of arithmetic processing is connected, and an operation unit including switches and the like for user operation and a liquid crystal display for performing various displays are provided. User interface 6
Is connected.

The telephone voice processing device 3 is connected to the portable telephone 1 by a connector 2, and inputs and outputs voice signals via a voice output line LU1 and a voice input line LD1.
The data output line LU2 and the data input line LD2
The input and output of data signals are performed via the. Note that the connector 2 and the mobile phone 1 are detachably connected, and the mobile phone 1 is easily detached from the connector 2 when getting off the vehicle, so that the mobile phone 1 can be used alone.

Next, details of the audio processing section 4 will be described. FIG. 2 is a circuit diagram showing a circuit configuration of the audio processing unit 4. It should be noted that most of the components of the audio processing unit 4 (excluding the analog-to-digital converter and the digital-to-analog converter) can be realized by arithmetic processing using a DSP.

An analog audio signal is input to an audio input line LD.
The signal is input to an analog-to-digital converter (A / D) 16 via the input unit 1 and is converted into a digital signal. The output signal of the A / D 16 is input to an adder 17 and a level adjuster 23 described later.
Is added to the output signal. The output signal of the adder 17 is input to a level adjuster 18 where the signal level is adjusted. The output signal of the level adjuster 18 is input to a digital / analog converter (D / A) 19, converted into an analog signal, and output to the speaker 11 via the power amplifier 8.

An analog audio signal from the microphone 10 is amplified (attenuated) to a predetermined level by an amplifier 15 and then input to an analog / digital converter (A / D) 14 where it is converted into a digital signal. The amplifier 15 is configured by an analog amplifier circuit, and its gain can be adjusted by a control signal from the outside (CPU 5). The output signal of the A / D 14 is input to the adder 13 and added to the output signal of the level adjuster 20 described later. The output signal of the adder 13 is input to the level adjuster 12, and the signal level is adjusted. The output signal of the level adjuster 12 is input to a band rejection filter (a characteristic of attenuating a signal in a frequency band of a traveling noise of an automobile) 11 for noise removal, and the traveling noise is removed. The output signal of the band rejection filter 11 is D / A1
0, converted to an analog signal and
Output to

The output signal of the adder 17 is supplied to an inverter 24.
Is also input and subjected to inversion processing. The inversion process can be realized by multiplying the input signal by -1. Inverter 24
Is input to the delay unit 21 and subjected to delay processing. The output signal of the delay unit 21 is input to the level adjuster 20, and the signal level is adjusted. The output signal of the level adjuster 20 is input to the adder 13, and is added to the output signal of the A / D.

The output signal of the band rejection filter 11 is also input to an inverter 25 and subjected to an inversion process. The output signal of the inverter 24 is input to a delay unit 22 and subjected to a delay process. The output signal from the delay unit 22 is a level adjuster 2
3 and its signal level is adjusted. The output signal of the level adjuster 23 is input to the adder 17, and the A / D1
6 is added to the output signal.

The delay units 21 and 22 are, for example, constituted by multi-stage memories in which input signals are sequentially shifted and stored, and the stored values of the last stage are output signals, and the number of stages is set by a control signal from the CPU 5. Thereby, the delay time is set. In addition, each level adjuster 12,1
In the digital signal processing, 8, 20, and 23 can be realized by multiplying the input signal by a coefficient, and the level adjustment amount is determined by setting the coefficient by a control signal from the CPU 5.

Next, the delay characteristics of the delay units 21 and 22, the level adjustment characteristics of the level adjusters 12, 18, 20 and 23, and the amplification characteristic of the amplifier 15 will be described. Delay device 2
1 and the level adjustment amount in the level adjuster 20 are the level adjuster 18, the D / A 19, the amplifier 8,
The change in the transmission time and the signal level when the signal is transmitted on the path to the adder 13 via the speaker 11, the vehicle interior space, the microphone 10, the microphone amplifier 9, the amplifier 15, and the A / D 14 are changed by the inverter 24, Delay device 21, level adjuster 2
The transmission time and the change in signal level when the signal is transmitted on the path leading to the adder 13 via 0 are set to be equal to each other. As a result, the adder 13 includes the level adjuster 18, the D / A 19, the amplifier 8, the speaker 11,
Car interior space, microphone 10, microphone amplifier 9, amplifier 1
5. A signal having the same phase and opposite phase is input from the level adjuster 20 to the echo signal transmitted through the A / D path 14, and added, so that the echo signal is deleted.

The delay amount in the delay unit 22 and the level adjustment amount in the level adjuster 23 are added to the adder 17 via the D / A 10, the transmitting circuit and the receiving circuit (wraparound) of the mobile phone 1, and the A / D 16. Changes in transmission time and signal level when a signal is transmitted on a path leading to adder 17 via inverter 25, delay unit 22 and level adjuster 23 when a signal is transmitted on a path leading to adder 17 Are set to be equal to the changes in the transmission time and the signal level, respectively. As a result, the adder 17 receives the D / A 10, the transmission circuit and the reception circuit (wraparound) of the mobile phone 1, and a signal having the same phase and the same phase as the echo signal transmitted through the path of the A / D 16. The echo signal is erased by being input from the bell adjuster 23 and added.

The level adjustment amount in the level adjuster 18 is adjusted so that the levels of the audio signals output from the level adjuster 18 are substantially the same. Therefore, the CPU 5
Captures the output signal from the A / D 16 and calculates the audio level of the received signal, and controls the level adjustment amount in the level adjuster 18 according to the calculated audio level.

The level adjustment amount in the level adjuster 12 is adjusted so that the levels of the audio signals output from the level adjuster 12 are substantially the same. Therefore, the CPU 5
Captures the output signal from the A / D 14, calculates the audio level of the received signal, and controls the level adjustment amount in the level adjuster 12 according to the calculated audio level.

The amplification characteristics of the amplifier 15 are set so that the level of the output signal does not exceed the maximum input level of the A / D 14. The value of the output signal of the D / A 19 is 15 output signal levels are set so as not to exceed.

Control values for realizing these operations are stored in the memory 7, and the CPU 5 outputs control values according to the operating conditions (vehicle type, output level of the reception signal and transmission signal, etc.) to each unit. It has become.

Next, the processing performed by the CPU 5 will be described. FIG. 3 is a flowchart showing the processing performed by the CPU 5. This process is performed at the start of a call.

First, in step S1, the transmission sound volume is measured from the output signal of the A / D 14, and the process proceeds to step S2. This measurement is performed during a predetermined time from the start of transmission in the absence of a received voice signal, and an average level is calculated. Step S
In 2, the received sound volume is measured from the output signal of the A / D 16,
Move to step S3. This measurement is performed during a predetermined time from the start of the reception, and the average level is calculated. Step S3
Then, the vehicle type set by the user interface 6 is fetched, and the process proceeds to step S4. In step S4, the noise level is fetched and the process proceeds to step S5. Step S
In step S5, a signal indicating the line echo mode, that is, whether or not the mobile phone side is performing the echo canceling operation of the line echo is recognized from the signal of the mobile phone 1, and step S5 is performed.
Move to 6.

In step S6, it is determined from the signal of the mobile phone 1 whether the call state is a one-way call or not, and in step S7
Move on to The recognition of the call state can be determined from the telephone number (for example, the corresponding number is stored in the memory 7 for identification, such as 177 of the weather forecast and 117 of the time signal). In step S7, the electric field intensity of the radio wave of the telephone is detected based on the signal from the mobile phone 1, and the process proceeds to step S8. In steps S1 to S7, the fetched or recognized data is stored in the memory 7 until the next call. In step S8, steps S1 to S7
The delay characteristics of the delay units 21 and 22 and the level adjusters 12 and
Level adjustment characteristics at 18, 20, and 23, amplifier 15
, A control value for setting the amplification characteristic is calculated, and the process proceeds to step S9.

In the memory 7, control values corresponding to various states fetched or recognized in steps S1 to S7 are stored as tables, and control values corresponding to the various states fetched or recognized by the CPU 5 are stored. The control value is calculated by searching for the control value. Specifically, the delay unit 2 is configured such that the level adjuster 12 attenuates the signal as the transmission volume increases, and the level adjuster 18 attenuates the signal as the reception volume increases.
1 and the level adjuster 20 have a delay characteristic and a level adjustment amount according to the vehicle type, and the higher the noise level is, the larger the noise removal amount of the band rejection filter 11 is. When the call state is one-way communication, a signal is output from the inverter 24, the delay unit 21, the delay unit 21, and so that the paths of the inverter 25, the delay unit 22, and the level adjuster 23 are cut off during the cancellation process. The control value is stored in the memory 7 so that the path of the level adjuster 20 is cut off, and the level adjusters 12 and 18 attenuate the signal greatly as the intensity of the radio wave received by the mobile phone 1 increases. Is stored. Then, in step S9, the control value calculated in step S8 is output to the audio processing unit 4, and the process ends.

Apart from these processes, the running noise level of the vehicle is always detected during a call, and the noise removal capability of the band rejection filter 11 increases as the noise level increases in accordance with the running noise level. (Increase the cutoff band and increase the amount of attenuation). still,
The running noise level is calculated based on a signal from a microphone provided at a position that does not pick up the driver's vocal sound and a signal from a vibration sensor that detects vibration of the vehicle. It is also possible to infer from the vehicle speed signal from the sensor.

According to the above processing, the telephone voice processing apparatus according to the present embodiment transmits a transmission signal whose voice level is adjusted in accordance with the volume of a speaker's utterance. The other party's playback volume is appropriate, preventing the other party's ears from being too loud and causing the other party's ears to hurt, and preventing the other party from understanding the content of the call because the volume is too low. can do. Also, since the speaker's utterance volume is detected when the reception signal at the start of the call is in a silent state, the speaker's utterance volume can be detected without being affected by the uttered voice of the other party, and the transmission signal level can be detected. Can be adjusted with high accuracy.

Also, since the sound reproduction level is adjusted according to the utterance volume of the other party, the reproduction volume from the speaker becomes appropriate, and the earpiece hurts the volume generated by the other party. Conversely, it is possible to prevent a situation in which the generated sound volume is too low to grasp the contents of the call. Since the reception volume is detected at the start of a call, the voice volume of the other party can be detected without being affected by the voice of one's own voice, for example, the influence of one's own voice wrapping around the handset of the other party and returning. The level of the received signal can be adjusted with high accuracy.

Further, since the echo cancellation signal is generated in accordance with the delay time and the amount of attenuation from the source signal of the echo which varies according to the vehicle type, effective echo removal according to the vehicle type is performed for any vehicle type. Will be

In addition, the vehicle noise is appropriately removed in accordance with the level of the running noise of the vehicle. That is, the noise removal amount is insufficient and the noise is conspicuous. It is possible to minimize the occurrence of a situation in which the situation becomes clearer.

The A / D 14 controls the amplifier so that the level of the output signal from the microphone 10 is lower than the level of the output signal to the speaker 11.
Is converted into a digital signal without causing an overflow or the like and using a wide conversion range, so that the conversion accuracy is increased, and as a result, the processing accuracy of the audio signal can be increased.

Also, when the echo cancellation processing is performed on the telephone side, the transmission echo cancellation processing is stopped, so that it is not necessary to use a circuit such as a memory separately for canceling the transmission echo. Since it can be used for cancellation, it is possible to accurately cancel the reception echo.

In addition, in the case of a one-way call such as a weather forecast or a time signal, unnecessary echo cancellation is not performed.
It is possible to prevent a situation in which the voice of the call becomes unclear due to the echo cancellation.

Further, since the transmission level and the reception level are adjusted in accordance with the electric field strength of the telephone communication, it is possible to suppress the fluctuation of the level of the reproduced sound on the self side and the communication partner side due to the electric field strength.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a telephone voice processing device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of an audio processing unit.

FIG. 3 is a flowchart illustrating a process performed by a CPU.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mobile telephone 2 ... Connector 3 ... Telephone audio processing device 4 ... Audio processing unit 5 ... CPU 10 ... Microphone 11 ... Speaker

Claims (11)

[Claims] 1. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. In a telephone voice processing apparatus for removing echoes mixed into a transmission signal by being input to a microphone, a voice volume detection means for detecting a voice volume of a speaker, and a voice volume detection means for detecting a voice volume detected by the voice volume detection means. And a transmission level adjusting means for adjusting the level of the transmission signal. 2. The telephone voice processing device according to claim 1, wherein said utterance volume detection means detects the utterance volume of the speaker when the reception signal at the start of the call is in a silent state. 3. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior, and receiving the telephone. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. A telephone voice processing apparatus for removing an echo mixed into a transmission signal by being input to a microphone, a reception volume detection unit for detecting a reception volume corresponding to a volume of a voice of the other party from the reception signal, and a reception volume. A telephone sound processor comprising: a reception level adjustment unit that adjusts a reproduction volume level of the reception voice signal according to the reception volume detected by the detection unit. Apparatus. 4. The telephone voice processing device according to claim 3, wherein said receiving sound volume detecting means detects the receiving sound volume at the start of a call. 5. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a partner and reproducing the voice of the partner from a speaker installed in the vehicle interior, and receiving the telephone. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing apparatus for removing echoes mixed in a transmission signal by being input to a microphone, wherein a vehicle type detecting means for detecting a vehicle type of the vehicle; A telephone speech processing apparatus comprising: condition setting means for setting conditions for generating an echo cancel signal. 6. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing apparatus for removing echoes mixed in a transmission signal by being input to a microphone, wherein a signal in a frequency band of a vehicle noise generated as the vehicle travels is removed from an input signal to the microphone. A vehicle noise filter; a vehicle noise level detecting means for detecting the level of the vehicle noise; and a vehicle noise level detected by the vehicle noise level detecting means. An operating condition setting means for setting an operating condition of the vehicle noise filter according to a bell. 7. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal by being input to a microphone, wherein a level of an output signal from the microphone is adjusted to be smaller than an output signal level to the speaker. And a microphone output adjusting means. 8. A hands-free telephone for transmitting voice input to a microphone installed in the vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior, and receiving the voice of the telephone. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing device for removing echo mixed into a transmission signal by being input to a microphone, wherein a transmission echo obtained by performing a delay process and performing a level adjustment on the transmission signal of the telephone. A transmission signal processing means for combining a cancel signal with the reception signal to remove an echo generated by mixing the transmission signal with the reception signal; Operation telephone speech processing apparatus characterized by comprising an operation switching means for switching the operation or non-operation of the transmission signal processing means in accordance with the. 9. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle interior to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal by being input to a microphone, comprising: a one-way call detection unit for detecting whether a call is a one-way call; A telephone voice processing apparatus comprising: echo removal processing stopping means for stopping echo removal processing when a one-way call is detected. 10. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle compartment to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior, and receiving the voice of the telephone. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal by being input to a microphone, comprising: an electric field intensity detecting means for detecting an electric field intensity of a reception signal of the telephone; And a transmission level adjusting means for adjusting a level of the transmission signal in accordance with the electric field strength obtained. 11. A hands-free telephone for transmitting voice input to a microphone installed in a vehicle compartment to a destination and reproducing the voice of the destination from a speaker installed in the vehicle interior. By combining the echo cancellation signal obtained by performing the signal delay processing and level adjustment with the input signal of the microphone to form a transmission signal, the reception voice signal reproduced from the speaker is converted to the reception voice signal. An in-vehicle telephone voice processing device for removing an echo mixed into a transmission signal by being input to a microphone, comprising: an electric field intensity detecting means for detecting an electric field intensity of a reception signal of the telephone; And a receiving level adjusting means for adjusting a level of the receiving signal in accordance with the received electric field strength.