JP4029769B2 - Voice input / output device and call system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is connected to a communication device that transmits / receives a voice signal for a call to / from an external device, converts ambient sound into a voice signal by a microphone, outputs the signal to the communication device, and is input from the communication device The present invention relates to a voice input / output device that outputs a voice signal to a speaker and generates a voice from the speaker, and a call system including the voice input / output device and a communication device.
[0002]
[Prior art]
Conventionally, a communication device that transmits and receives a voice signal for a call to and from an external device, and a peripheral device that is connected to the communication device is converted into a voice signal by a microphone (hereinafter referred to as a microphone) and output to the communication device. In addition, a call system is known that includes an audio input / output device that outputs an audio signal input from a communication device to a speaker and generates audio from the speaker.
[0003]
For example, a voice input / output device that inputs and outputs voice with a microphone and a speaker arranged in the vehicle so that the driver does not interfere with driving when the driver makes a call with a mobile phone in the vehicle is used as a communication device. There is known a call system for making a hands-free call in which a driver makes a call without holding the mobile phone by hand by connecting to the mobile phone.
[0004]
In such a call system, since there is a space between the microphone and speaker and the user, noise such as wind noise from the window in the vehicle and blowing sound from the air conditioner is mixed in the voice during the call. If the user cannot hear the sound from the speaker, or noise is superimposed on the sound input from the microphone, the sound heard by the other party may become unclear, making it difficult to talk. It is done.
[0005]
In order to improve this problem, the volume of the speaker is changed in accordance with the magnitude of the noise component in the audio signal input from the telephone microphone so that it can be heard easily (for example, the volume is increased when the noise is large). A voice input / output device is known (see Reference 1).
[0006]
There is also known a voice input / output device that performs processing such as filtering to reduce a noise component with respect to a voice signal from a microphone.
[0007]
[Reference 1]
JP-A-6-132848
[0008]
[Problems to be solved by the invention]
However, even if the volume of the speaker is varied according to the magnitude of the noise component, the problem caused by the noise superimposed on the sound input by the microphone is not improved, and the noise superimposed on the sound input by the microphone is not improved. Even in a voice input / output device that reduces noise by using a filter, it is difficult to sufficiently reduce noise in a frequency band close to that of a human voice because it is desired not to reduce the voice of the user.
[0009]
On the other hand, when a call becomes difficult due to noise, it is conceivable that a user can make a good call by setting a noise source around the user to a state where noise is not generated as much as possible. For example, in a running vehicle, a user performs noise reduction measures such as closing a window so that wind noise does not occur or stopping an air conditioner to eliminate a blowing sound.
[0010]
However, because of differences in the voice input position and sound collection characteristics between the user and the microphone, there is a difference between the surrounding voice heard by the user and the voice input by the microphone. There may be a case where an oversight occurs in the reduction treatment and a large noise remains in the voice input by the microphone. For example, there is a microphone near the air outlet of the air conditioner, and even if the sound of the air conditioner is greatly mixed in the sound input by the microphone, the sound of the air conditioner is heard at the user's ear position and the call is made. For example, it may be judged that the influence of the air conditioner is small and the sound of the air conditioner is left as it is.
[0011]
For this reason, even if the other party is listening to a voice that includes noise and is difficult to hear, the user cannot confirm the voice input by the microphone.
The present invention has been made in view of these problems, and enables a user to confirm noise included in sound input from a microphone when a call is performed using a voice input / output device. With the goal.
[0012]
[Means for Solving the Problems]
  The voice input / output device according to claim 1, wherein the voice input / output device according to claim 1 is connected to a communication device that transmits / receives a voice signal for a call to / from an external device, and the surrounding voice is voiced by a microphone. While converting into a signal and outputting to a communication apparatus, the audio | voice signal input from the communication apparatus is output to a speaker, and a sound is generated from a speaker.In particular, the voice input / output device is mounted on a vehicle, and the microphone and the speaker are provided in the vehicle interior so as to enable a hands-free call in the vehicle interior.
[0013]
And it is characterized by providing the loopback means which outputs at least one part of the audio | voice signal input from the microphone to a speaker, and produces | generates the surrounding audio | voice which the microphone converted into the audio | voice signal from a speaker.
As a result, according to the voice input / output device of the present invention, the surrounding voice input from the microphone is generated from the speaker by the loopback means. It is possible to confirm how much noise is included and how much noise is included without overlooking the noise source that has a large effect on the call.
[0014]
Then, when the user performs a measure for reducing the noise with respect to the noise source specified in this way, it is possible to prevent a call failure due to the noise.
In addition, noise reduction measures can be kept to the minimum necessary, and it can be confirmed that the other party is not difficult to hear.
[0015]
The voice input / output device is configured separately from the communication device as in the conventional example, or is configured using a microphone and a speaker built in a telephone terminal or the like, and is integrated with the communication device. There are various things. In addition, even if the voice input / output device is configured separately from the communication device, it is used by being mounted on a vehicle, etc., or it is held on a part of the user's body with a headset etc. There are things that are not.
[0016]
  In the voice input / output device according to claim 1, the loopback means receives a recording command via an operation unit provided in the voice input / output device for commanding the operation of the loopback means by an external operation. Then, the sound signal input from the microphone by the recording means is stored in a predetermined storage medium, and when the reproduction command is input via the operation unit, the sound signal stored in the storage medium is input by the reproduction means. Output to the speaker and generate sound from the speaker.
[0017]
  As a result, according to the voice input / output device of the first aspect, the user inputs the recording command at the time of the telephone call and only stores the voice signal, and inputs and stores the reproduction command after the telephone call ends. The reproduced audio signal can be reproduced, and the content of noise included in the audio signal can be confirmed. In this way, if the content of noise is confirmed after the call, it can be confirmed calmly, and in the same situation during the next call, noise reduction measures can be taken without confirming the content of the audio signal. Can be done.
[0018]
  In the audio input / output device according to claim 1, the loopback unit outputs the audio signal input from the microphone to the speaker by the direct reproduction unit when the direct reproduction command is input via the operation unit. Then, sound is generated from the speaker.
[0019]
  As a result, according to the voice input / output device of the first aspect, the user directly inputs a reproduction command at an arbitrary time and confirms the content of the voice signal output by the voice input / output device at that time. be able to.
In addition, as described in the prior art, noise often becomes a problem when hands-free calling is performed in a vehicle, and there are many noise sources in the vehicle that can confirm noise content and take measures to reduce noise.
[0020]
  In this respect, when the input / output device is mounted on a vehicle as in the voice input / output device of claim 1 and the microphone and the speaker are provided in the vehicle interior so as to enable hands-free calling in the vehicle interior. The effect of the present invention is great.
[0021]
  In addition, since the operation unit for instructing the operation of the loopback unit by an external operation is provided, the user commands the operation of the loopback unit by the operation unit and is included in the sound input by the microphone. It is possible to check the generated noise and operate it only during the noise reduction treatment of the noise source, and then stop the loopback means so that the sound generated from the speaker can be easily heard without the sound of the loopback means.
[0022]
  By the way, when the speaker of the voice input / output device is not attached to the user's ear like a headset speaker or an earphone, but is attached away from the user in a car or the like, the loopback means may When the sound signal input from the speaker is generated as a sound from the speaker, the sound from the speaker spreads to the surroundings and is input to the microphone again, and is repeatedly generated from the speaker, causing an echo or howling, There may be a case where the call is disturbed.
[0023]
  Therefore, the voice input / output device of the present invention is preferably provided with an echo canceling means for removing the voice signal component generated from the speaker from the voice signal input from the microphone.
That is, in this way, the audio signal component generated from the speaker can be prevented from being generated again from the speaker, and echo and howling can be prevented.
[0024]
  by the way,Vehicles are usually equipped with in-vehicle devices that output sound from speakers, such as audio equipment and car navigation devices, and in-vehicle devices that input sound from a microphone, such as a speech recognition device for operating these with voice commands Installed.
[0025]
  Therefore, it is a voice input / output device mounted on a vehicle.1 or claim 2The voice input / output device according to claim 13As described above, the switching means switches at least one of the output destination of the audio signal input from the microphone and the input source of the audio signal output to the speaker to an in-vehicle device other than the communication device, and the audio input / output device May be shared by the communication device and other in-vehicle devices.
[0026]
  That is, in this way, the microphone or speaker can be shared with other in-vehicle devices, and the number of microphones or speakers mounted on the vehicle may be reduced.
  Meanwhile, claims4In the communication system described in (1), a communication device that transmits and receives audio signals for calls to and from an external device, and a communication device that is connected to the communication device, converts surrounding audio into an audio signal using a microphone, and outputs the audio signal to the communication device. A voice input / output device that outputs a voice signal input from a communication device to a speaker and generates a voice from the speaker.3A voice input / output device according to any one of the above.
[0027]
  As a result, the present invention (claims)4According to the call system according to claim 1, claims 1 to3It is possible to provide a call system having the same effect as the voice input / output device described in 1.
  Claims4In particular, the call system according to claim 15As described above, the communication device is preferably composed of a portable radio telephone terminal.
[0028]
That is, when the communication device is a portable wireless telephone terminal (so-called mobile phone), the communication device is often used in a noisy environment such as outdoors, and thus the effect of the present invention is great.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
A block diagram showing the overall configuration of the hands-free call system 1 of this embodiment is shown in FIG.
[0030]
The hands-free call system 1 includes a voice input / output device 2 attached to a vehicle and a portable radio telephone terminal (hereinafter referred to as a mobile phone) 50 connected to the voice input / output device 2. This is a system for a person to make a call with a user of another telephone terminal without holding the mobile phone 50 by hand.
[0031]
Note that the mobile phone 50 is held in a state of being electrically connected to the voice input / output device 2 by a holder (not shown) provided in the vehicle for holding the mobile phone 50.
The mobile phone 50 is capable of making a call by transmitting and receiving a voice signal by wireless communication with a single phone terminal or by using a voice signal input / output from the voice input / output device 2. Yes.
[0032]
The voice input / output device 2 includes a microphone 10, a speaker 20, a filter unit 30, and a loopback unit 40.
The microphone 10 converts an input voice into a voice signal based on an analog voltage and outputs the voice signal. The microphone 10 extends from the upper part of the front pillar of the driver's seat of the vehicle and has a driver's mouth at the tip of a column whose tip position is movable. It is attached towards.
[0033]
The speaker 20 converts an audio signal based on the input analog voltage and outputs a sound. The speaker 20 is mounted near the headrest of the driver's seat so as to output the sound at the driver's ear. The speaker 20 is provided with an audio signal amplifier and a volume for adjusting the amplification factor of the amplifier, and the output volume changes in accordance with the volume operation of the user.
[0034]
The filter unit 30 is disposed between the microphone 10 and the speaker 20 and the mobile phone 50, inputs the audio signal from the microphone 10, outputs the audio signal to the mobile phone 50, and inputs the audio signal from the mobile phone 50. And connected to the speaker 20 for output.
[0035]
The filter unit 30 includes a codec 31, an echo canceller 32, a noise canceller 33, a line echo canceller 34, and a codec 35. The codecs 31 and 35 include encoders 31a and 35b and decoders 31b and 35a, respectively. The encoders 31a and 35b convert input analog audio signals into digital audio data, and decoders 31b and 35a. Converts the input digital audio data into an analog audio signal. Data is transmitted between the encoder 31a and the decoder 35a and between the encoder 35b and the decoder 31b by digital serial communication.
[0036]
The echo canceller 32 takes in the audio data input to the decoder 31b of the codec 31, multiplies the value of the audio data by a preset gain by the amplifier 32a, inverts the polarity, and adds the audio data. The adder 32b adds (that is, subtracts) the audio data from the encoder 31a of the codec 31. In this way, the echo canceller 32 removes the sound signal of the component that the sound output from the speaker 20 is input by the microphone 10. The echo canceller 32 is provided with a volume 32c, and the gain of the amplifier 32a can be changed by operating the volume 32c by the user. The gain of the amplifier 32a is changed so as not to cause echo or howling according to the volume of the speaker 20 or the distance between the speaker 20 and the microphone 10.
[0037]
The noise canceller 33 is composed of a digital filter, and converts the audio data from the adder 32b to audio data of only audio components in an audible frequency band (for example, 20 to 20 kHz) and outputs the audio data to the decoder 35a of the codec 35. That is, the noise canceller 33 cuts the audio signal component outside the frequency band that can be heard by humans as noise.
[0038]
The line echo canceller 34 also receives the audio data output from the noise canceller 33, multiplies the gain set in advance by the amplifier 34a, inverts the polarity, and adds from the encoder 35b of the codec 35 by the adder 34b. Is added (that is, subtracted) to the audio data of No. 1 and output to the decoder 31b of the codec 31. In this way, the line echo canceller 34 outputs the audio signal transmitted from the mobile phone 50 as audio from the speaker of the telephone terminal of the other party, and is input again by the microphone of the telephone terminal of the other party to the mobile telephone 50. The audio signal component that returns is removed.
[0039]
In this manner, the filter unit 30 converts the analog audio signal input from the microphone 10 into digital audio data by the codec 31, removes part of the noise through the echo canceller 32 and the noise canceller 33, and outputs to the codec 35. The data is transmitted, converted again to an analog audio signal by the codec 35, and output to the mobile phone 50. Then, an analog voice signal input from the mobile phone 50 from the other party is converted into digital voice data by the codec 35, a part of noise is removed through the line echo canceller 34, and transmitted to the codec 31. At 31, the signal is converted back to an analog audio signal and output to the speaker 20.
[0040]
On the other hand, the loopback unit 40 includes a CPU 41, a memory 45, a converter 43, a power switch 47, a changeover switch 48, a regeneration switch 49, and an automatic call receiver 39.
The converter 43 includes an S / P converter 43a that converts serial communication data into parallel communication data, and a P / S converter 43b that converts parallel communication data into serial communication data. The unit 43a converts the serial communication data of the audio signal output from the noise canceller 33 into parallel communication data, and sends it to the CPU 41 via the bus line. The P / S converter 43b converts parallel communication data sent from the CPU 41 via the bus line 42 into serial communication data, and adds it to the audio data output from the encoder 35b of the codec 35 by the adder 37. To do. The audio data added by the adder 37 is sent to the decoder 31b, converted into an analog audio signal, and output from the speaker 20 as audio.
[0041]
The memory 45 has a capacity for storing audio signals for a predetermined time (for example, about 1 minute), and audio data is written and read by the CPU 41 via the bus line 42. Note that the CPU 41 returns to the top of the storage area and performs overwriting for writing audio data exceeding a predetermined time.
[0042]
The power switch 47 is a switch for switching the operation state of the loopback unit 40 to operation, stop, or automatic operation, and includes a 3-position toggle switch and is connected to the CPU 41. Then, the CPU 41 determines that one of the toggle positions of the power switch 47 is “ON”, the other is “AUTO”, and the other is “OFF”.
[0043]
The changeover switch 48 is a switch for changing the operation contents when the loopback unit 40 enters an operating state, and is constituted by a two-position toggle switch or the like, and is connected to the CPU 41. Then, the CPU 41 determines that one of the toggle positions of the changeover switch 48 is “recording” and the other is “direct playback”.
[0044]
The regeneration switch 49 is a switch for switching whether or not to perform the regeneration operation. The regeneration switch 49 includes a two-position toggle switch and is connected to the CPU 41. Then, the CPU 41 determines that one of the toggle positions of the regeneration switch 49 is “ON” and the other is “OFF”.
[0045]
Further, the automatic call receiver 39 is connected to the mobile phone 50, detects that an incoming call from another telephone terminal is present in the mobile phone 50, and outputs an incoming call detection signal to the CPU 41.
Further, the CPU 41 detects the state of the power switch 47, the changeover switch 48, the reproduction switch 49, and the incoming call detection signal from the automatic call receiver 39, and inputs / outputs voice data to / from the converter 43 and voice to the memory 45 Data is read and written via the bus line 42.
[0046]
Here, the processing procedure of the CPU 41 of the loopback unit 40 will be described with reference to the flowchart of FIG.
First, in S100, it is determined whether or not the power switch 47 is “ON”. If the power switch 47 is “ON”, the process proceeds to S130 for recording or direct reproduction, and must be “ON”. If so, the process proceeds to S110.
[0047]
In S110, it is determined whether or not the power switch 47 is “AUTO”. If the power switch 47 is “AUTO”, the process proceeds to S120 in order to determine whether or not there is an incoming call detection signal, and must be “AUTO”. If so, the process proceeds to S160.
In S120, the incoming call detection signal from the automatic call receiver 39 is detected, and if the incoming call detection signal is detected, the process proceeds to S130 for recording or direct reproduction, and if the incoming call detection signal is not detected, the process proceeds to S160. To do.
[0048]
Next, in S130, it is determined whether or not the changeover switch 48 is “recording”. If the changeover switch 48 is “recording”, the process proceeds to S140. In S140, the S / P conversion of the converter 43 is performed. The audio data input from the unit 43a is written into the memory 45, and the process returns to S100. If the changeover switch 48 is not “recording” but “direct playback”, the process proceeds to S150, and the audio data from the S / P conversion unit 43a of the converter 43 is converted to P of the converter 43 in S150. The data is output to the / S conversion unit 43b, the sound is output from the speaker 20, and the process returns to S100.
[0049]
In S160, it is determined whether or not the reproduction switch 49 is “ON”. If the reproduction switch 49 is “ON”, the process proceeds to S170, and the audio data stored in the memory 45 is read and the converter 43 is read. Are output to the P / S conversion unit 43b, the sound is output from the speaker 20, and the process returns to S100. If the regeneration switch 49 is not “ON”, the process directly returns to S100.
[0050]
As described above, when the user switches the power switch 47 to “ON” in the state where the changeover switch 48 is switched to “recording”, the audio data of the audio signal input from the microphone 10 is stored in the memory 45. The
When the user switches the power switch 47 to “OFF” and switches the reproduction switch 49 to “ON”, the sound based on the sound data stored in the memory 45 is output from the speaker 20. Further, when the power switch 47 is switched to “AUTO” and the incoming call detection signal from the automatic call receiver 39 is not detected, the same operation is performed even if the playback switch 49 is switched to “ON”.
[0051]
Further, when the power switch 47 is switched to “ON” in a state where the changeover switch 48 is switched to “direct reproduction”, the audio signal input from the microphone 10 is output from the speaker 20 as it is.
Further, when the power switch 47 is switched to “AUTO”, when the mobile phone 50 receives a call and an incoming call detection signal is output from the automatic call receiver 39, it is the same as when the power switch 47 is switched to “ON”. Operation is performed.
[0052]
As described above, according to the voice input / output device 2 of the hands-free call system 1, the surrounding voice converted into the voice signal by the microphone 10 can be generated from the speaker 20, and the user can hear the voice from the speaker 20. , And confirms what kind of noise is contained in the voice heard by the other party, and identifies a noise source that has a large effect on the call. As a result, the user can take measures to reduce the noise with respect to the identified noise source, thereby preventing poor communication due to the noise.
[0053]
In addition, the voice signal transmitted to the other party can be confirmed on the spot by listening to the surrounding voice converted into the voice signal by the microphone 10 by operating the power switch 47, the changeover switch 48, and the playback switch 49. Then, it can be stored once in the memory 45 and listened to later. If the power switch 47 is set to “AUTO”, the mobile phone 50 is automatically played back or recorded automatically when it is in a call state, and the user does not need to operate it.
[0054]
Further, the echo canceller 32 removes the audio signal component output from the speaker 20 from the audio signal input from the microphone 10 so that no echo or howling occurs.
[Relationship with the present invention]
The loopback unit 40 of this embodiment corresponds to the loopback unit of the present invention, the echo canceller 32 corresponds to the echo cancellation unit, the power switch 47, the changeover switch 48, and the reproduction switch 49 correspond to the operation unit, The processing operation at S130 and S140 corresponds to the recording means, the processing operation at S160 and S170 corresponds to the reproduction means, and the processing operation at S150 corresponds to the direct reproduction means.
[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to said specific embodiment, It can implement with a various form besides this.
[0055]
For example, in the present embodiment, the hands-free call system 1 for performing hands-free calls in a vehicle has been described. However, the present invention is not limited to this, and a voice input / output device including a microphone and a speaker is integrated with a headset. Is not limited, and may be configured as a voice input / output device in which a loopback unit 40 is attached to a microphone and a speaker built in a fixed telephone and used in a home.
[0056]
Further, although the speaker 20 is mounted around the headrest of the seat, the speaker or the like that is mounted around the instrument panel and is normally used in an audio device is used as the speaker 20 of the hands-free call system 1, and the audio device or the like. A communication line 60 such as a LAN connected to another in-vehicle device is connected to the CPU 41, audio data is input from the in-vehicle device connected to the communication line 60 to the CPU 41, and is output from the P / S conversion unit 42 b of the converter 43. The speaker 20 may be configured to output sound. That is, if comprised in this way, the speaker 20 can be shared by the hands-free telephone call system 1 and another vehicle-mounted apparatus, and the number of components mounted in a vehicle can be reduced. Similarly, the microphone 10 may be configured to be shared with other in-vehicle devices.
[0057]
Further, the loopback unit 40 may be provided with a timer, and the processing of S140 or S150 may be performed only for a preset time. That is, with this configuration, it is possible to eliminate the operation of switching the power switch 47 to “OFF” after the loopback unit 40 is operated and noise reduction is performed.
[0058]
The voice input / output device 2 performs digital conversion by the filter unit 30 to perform noise removal and serial communication. However, the voice input / output device 2 may be configured by a circuit that transmits an analog voltage voice signal. In this case, the loopback unit 40 may convert the converter 43 from analog to digital by the S / P conversion unit 43a and digital to analog conversion by the P / S conversion unit 43b.
[0059]
Furthermore, although the voice input / output device 2 is provided with the filter unit 30, the filter unit 30 may not be provided, and the microphone 10 and the speaker 20 may be directly connected to the mobile phone 50. Alternatively, the loopback unit 40 may be connected to a microphone and a speaker built in the mobile phone 50.
[0060]
The loopback unit 40 controls the input / output of audio data by the CPU 41 so as to perform loopback. However, only the synthesizer that synthesizes the audio signal from the microphone 10 with the audio signal to the speaker 20. It may be configured, or may be configured to record and reproduce with an analog device such as a tape recorder instead of the memory 45.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the overall configuration of the present embodiment.
FIG. 2 is a flowchart showing a processing procedure in a CPU 41 of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hands-free call system, 2 ... Voice input / output device, 10 ... Microphone, 20 ... Speaker, 30 ... Filter part, 31 ... Codec, 32 ... Echo canceller, 33 ... Noise canceller, 34 ... Line echo canceller, 35 ... Codec, 37 ... adder, 39 ... automatic receiver, 40 ... loopback unit, 42 ... bus line, 43 ... converter, 45 ... memory, 47 ... power switch, 48 ... switch, 49 ... playback switch, 50 ... cell phone 60 ... communication line.

Claims (5)

Connected to a communication device that transmits and receives a voice signal for a call to and from an external device, converts surrounding voice into a voice signal with a microphone, outputs the voice signal to the communication device, and inputs the voice signal from the communication device In a voice input / output device that generates a voice from the speaker,
The voice input / output device is mounted on a vehicle, and the microphone and the speaker are provided in the vehicle interior so as to enable hands-free calling in the vehicle interior.
Loopback means for outputting at least a part of an audio signal input from the microphone to the speaker and generating ambient audio from the speaker, which is converted into an audio signal by the microphone ;
The loopback means includes
When a recording command is input via an operation unit provided in the voice input / output device in order to command the operation of the loopback means by an external operation, the voice signal input from the microphone is stored in a predetermined storage medium. Recording means to
When a playback command is input via the operation unit, a playback unit that outputs a sound signal stored in the storage medium to the speaker and generates sound from the speaker;
Direct reproduction means for outputting a sound signal input from the microphone to the speaker and generating sound from the speaker when a direct reproduction command is input via the operation unit;
A voice input / output device characterized by comprising:   2. An audio input / output device according to claim 1, further comprising echo canceling means for removing an audio signal component generated from the speaker from an audio signal input from the microphone. At least one of an output destination of an audio signal input from the microphone and an input source of an audio signal output to the speaker is switched to an in-vehicle device other than the communication device, and the audio input / output device is connected to the communication device. 3. The voice input / output device according to claim 1, further comprising switching means for sharing with other in-vehicle devices. A communication device for transmitting and receiving voice signals for communication with an external device;
  Connected to the communication device, converts surrounding sound into a sound signal with a microphone and outputs it to the communication device, and outputs a sound signal input from the communication device to a speaker to generate sound from the speaker A voice input / output device
  A call system comprising:
  4. A call system comprising the voice input / output device according to claim 1 as the voice input / output device. The call system according to claim 4, wherein the communication device is a portable radio telephone terminal.

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