JP2000350266A - System and method for sound signal distribution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly obtain the same sound signal as at the transmission side by decoding a encoded sound signal sent from the transmission side on a reception side. SOLUTION: After encoding process of a sound encoding device 101 is initialized after a call connection is confirmed after a 1st radio terminal set 102 is called, a input sound signal 110 is encoded, the encoded sound signal and the initialization signal for the initialization are multiplexed, and the multiplexed signal is received by a called-size 2nd radio terminal set 104 having a call connection with the 1st radio terminal set 102; and a sound decoding device 105 separates the multiplexed signal into the encoded sound signal and initialization signal and after a decoding process is initialized hen the separated initialization signal is inputted, the encoded sound signal is decoded to obtain a decoded sound signal 115.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal distribution system and method capable of properly transmitting an audio signal from a transmitting side to a receiving side between wireless terminals (mobile stations) in a mobile communication system.

[0002]

2. Description of the Related Art Conventionally, as this kind of sound signal distribution system and method, there is one disclosed in Japanese Patent Application Laid-Open No. 5-75708.

FIG. 7 is a block diagram showing a configuration of a conventional audio signal distribution system.

An acoustic signal distribution system 70 shown in FIG.
0 is the audio encoding device 701 and the first wireless terminal 702
, A transmission path 703, a second wireless terminal 704, and an audio decoding device 705.

[0005] However, the first wireless terminal 702 and the second wireless terminal 704 are portable telephones and information terminal devices having a personal computer function. The audio decoding device 705 has a built-in configuration or is connected by wiring.

An audio encoding device 701 includes an audio encoding unit 801 shown in FIG. 8, and the audio encoding unit 801 encodes an input audio signal 706 to generate an audio encoded signal 707. .

The first wireless terminal 702 has a transmission / reception function, and transmits a transmission signal 708 obtained by modulating a radio frequency with an acoustic coded signal 707 by radio waves.

[0008] The transmission path 703 is a system for transmitting the transmission signal 708, and includes air, electric wires, or communication equipment such as a radio telephone base station and a telephone exchange through which the transmission signal 708 passes. .

The second wireless terminal 704 has a transmission / reception function, and has a transmission signal 70 transmitted through the transmission path 703.
8 is output, and a received audio coded signal 709 is output.

The audio decoding apparatus includes an audio decoding unit 901 shown in FIG. 9 and generates a decoded audio signal 710 by decoding the received audio coded signal 709 by the audio decoding unit 901. is there.

In such a configuration, a call is made from the receiving side of the acoustic signal to the transmitting side, and after the call is connected by the calling, the transmitting side starts encoding of the acoustic signal in real time, and the acoustic encoding obtained by this is performed. A case will be described in which a signal is transmitted to a receiving side by wireless communication, and the receiving side decodes the acoustic coded signal to obtain an original acoustic signal.

First, the second wireless terminal 704 on the receiving side makes a call to the first wireless terminal 702 on the transmitting side. As a result, both terminals 704 and 702 are connected via the transmission path 703.

After this connection, the input audio signal 706 is converted into an audio encoded signal 707 by the audio encoding device 701, and the audio encoded signal 707 is converted to the first wireless terminal 702.
Is transmitted as a transmission signal 708 to the second wireless terminal 704 via the transmission path 703.

The transmission signal 708 received by the second wireless terminal 704, that is, the received audio coded signal 709 is converted into a decoded audio signal 710 by the audio decoding device 705.

[0015]

However, in the conventional apparatus, in audio encoding, encoding may be performed using the correlation of the previous frame or the like. Processing must be performed from the first frame. However, the audio decoding device 705 starts the audio decoding process immediately after the call connection is completed.
There is no guarantee that the reception of the received acoustic coded signal 709 is performed immediately after connection. For this reason, the audio encoding device 7
There is a possibility that an error occurs in the initial state of various information in the audio decoding device 705 and the audio signal decoded by the audio decoding device 705.
There is a problem that the sound signal is different from the sound signal coded in the step (1).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an audio coded signal transmitted from a transmission side, which can be decoded at a reception side to appropriately obtain the same audio signal as that of the transmission side. It is an object to provide a signal distribution system and method.

[0017]

According to the present invention, after confirming a call connection after an incoming call to a first wireless terminal, an encoding process of an acoustic encoding device is initialized, and then an acoustic signal is encoded. The coded signal is multiplexed with the initialized signal, and the multiplexed signal is received by a second wireless terminal on the calling side connected to the first wireless terminal. The decoded signal is separated into an encoded audio signal and an initialization signal by an audio decoding device, and when the separated initialization signal is input, a decoding process is initialized, and then the encoded audio signal is decoded to obtain an audio signal. I did it.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first aspect of the present invention is directed to a first wireless terminal for wirelessly transmitting and receiving a signal, and initialization when a call connection to the first wireless terminal after receiving a call is confirmed. Call connection confirmation means for outputting a notification signal, encoding means for generating an audio encoded signal by encoding an audio signal after initializing an encoding process upon input of the initialization notification signal, the audio encoded signal, and An audio encoding device including multiplexing means for multiplexing the initialization notification signal and outputting the multiplexed signal to the first wireless terminal; A wireless terminal, separating means for separating the multiplexed signal received by the second wireless terminal into the acoustic coded signal and the initialization notification signal, decoding when the separated initialization notification signal is input The separated audio coding after initializing the processing A configuration having a, a sound decoding apparatus comprising decoding means for obtaining the acoustic signal by decoding the issue.

According to this configuration, the audio decoding device is initialized with the signal obtained by initializing the audio encoding device.
No error occurs in the initial state of both devices,
As a result, the encoded audio signal transmitted from the transmitting side can be decoded at the receiving side to properly obtain the same audio signal as that of the transmitting side, whereby the decoded audio signal of the receiving side can be obtained. Sound quality can be improved.

According to a second aspect of the present invention, in the first aspect, the audio coding apparatus comprises: a second decoding means for decoding an audio coded signal from the coding means; Detecting means for detecting an abnormal sound included in the sound signal, and outputting an abnormal sound detection signal indicating the detected abnormal sound, and removing means for removing the abnormal sound indicated by the abnormal sound detection signal in the audio encoded signal. Wherein the multiplexing means multiplexes the acoustic coded signal from which the abnormal noise has been removed and the initialization notification signal.

According to this configuration, the rate of occurrence of abnormal noise in the decoded audio signal can be reduced on the receiving side.

According to a third aspect of the present invention, in the first aspect or the second aspect, the first wireless terminal is provided with another plurality of second wireless terminals.
A function of transmitting and receiving to and from a wireless terminal, wherein each time a call connection by an incoming call from each of the plurality of second wireless terminals is executed in the first wireless terminal, an encoding process is initialized by an acoustic encoding device. After receiving the multiplexed signal in which the initialization notification signal is multiplexed by each of the call-connected second wireless terminals, the audio decoding device connected to each of the second wireless terminals receives the multiplexed signal. A configuration is adopted in which the decoding process is separated using the separated initialization notification signal.

According to this configuration, even when one audio encoding device and a plurality of audio decoding devices are connected,
Since each audio decoding device is initialized with the signal obtained by initializing the audio encoding device, no error occurs in the initial state of both devices, and as a result, the audio code transmitted from the transmitting side is eliminated. The decoded signal can be decoded by a plurality of receiving sides to properly obtain the same acoustic signal as that of the transmitting side. As a result, it is possible to improve the sound quality of the decoded sound signal on the plurality of receiving sides.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the audio decoding apparatus receives an incoming call request from another wireless terminal while receiving the audio coded signal. In such a case, an incoming message notification means for generating an incoming message signal in the event of occurrence and a mixing means for mixing and outputting the sound signal decoded by the decoding means and the incoming message signal are adopted.

According to this configuration, even when the audio signal is being decoded, it is possible to reliably confirm that there is an incoming call from another wireless terminal.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, an audio encoding device is built in the first wireless terminal, and an audio decoding device is installed in the second wireless terminal. Uses a built-in configuration.

According to this configuration, the audio signal can be properly encoded or decoded by the wireless terminal.

According to a sixth aspect of the present invention, a mobile communication system is provided with the audio signal distribution system according to any one of the first to fifth aspects.

According to this configuration, the same function and effect as any one of the first to fifth aspects can be obtained in the mobile communication system.

According to a seventh aspect of the present invention, after confirming a call connection after an incoming call to a wireless terminal, an encoding process of an acoustic encoding device is initialized, and then an acoustic signal is encoded. And the initialized signal subjected to the initialization, and the multiplexed signal is received by a calling-side wireless terminal connected to the wireless terminal in a call connection. In the separated audio encoded signal and the initialization signal,
After the decoding process is initialized by the separated initialization signal, the separated audio encoded signal is decoded to obtain an audio signal.

According to this method, the audio decoding device is initialized with the signal obtained by initializing the audio encoding device.
No error occurs in the initial state of both devices,
As a result, the encoded audio signal transmitted from the transmitting side can be decoded at the receiving side to properly obtain the same audio signal as that of the transmitting side, whereby the decoded audio signal of the receiving side can be obtained. Sound quality can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an audio signal distribution system according to Embodiment 1 of the present invention.

The acoustic signal distribution system 10 shown in FIG.
0 is the audio encoding device 101 and the first wireless terminal 102
, A transmission path 103, a second wireless terminal 104, and an audio decoding device 105.

However, the first wireless terminal 102 and the second wireless terminal 104 are a portable telephone or an information terminal device having a personal computer function. The audio decoding device 105 has a built-in configuration or is connected by wiring.

As shown in FIG. 2, the audio encoding device 101 includes an audio encoding unit 200, a call connection confirmation unit 201, and a multiplexing unit 202. From the input audio signal 110 to the audio encoded signal 21
0 is output to the multiplexing unit 202, and the call connection confirmation unit 2
01, when the incoming call signal 112 is input, the initialization notification signal 211 is output to the audio encoding unit 200 and the multiplexing unit 202, and the multiplexing unit 202 outputs the audio encoded signal 210 and the initialization notification signal 211. Are multiplexed, and this is output signal 11
1 is output to the first wireless terminal 102.

The first wireless terminal 102 has a transmission / reception function, and transmits the transmission signal 1 in which the output signal 111 modulates the radio frequency.
13 and transmits an incoming call signal 112 to the audio encoding apparatus 101 when there is an incoming call request from another terminal.
Output to

The transmission path 103 is a system for transmitting the transmission signal 113. The transmission path 103 includes air, electric wires, or communication equipment such as a base station for a radio telephone and a telephone exchange through which the transmission signal 113 passes. .

The second wireless terminal 104 transmits the transmission signal 113
And converts it into an input signal 114, which is output to the audio decoding device 105.

As shown in FIG. 3, the audio decoding apparatus 105 includes a separating unit 300 and an audio decoding unit 301. The separating unit 300 converts the input signal 114 into the received audio encoded signal 310 and The audio signal is separated into a reception initialization notification signal 311, and the audio
By decoding 0, a decoded audio signal 115 is created.

The operation when a call is made from the second wireless terminal 104 on the receiving side to the first wireless terminal 102 on the transmitting side in such a configuration will be described.

When a call is made from the second wireless terminal 104 to the first wireless terminal 102, the first wireless terminal 1
02 is a call connection confirmation unit 201 in the audio encoding device 101 which receives an incoming signal 112 indicating that there is an incoming call from another terminal.
Output to

After confirming the call connection based on the incoming call signal 112, the call connection confirmation unit 201 outputs an initialization notification signal 211 to the audio encoding unit 200 and the multiplexing unit 202. At this time, the audio encoding unit 200 may or may not perform the encoding process of converting the input audio signal 110 into the audio encoded signal 210. However, if the encoding process has not been performed, the acoustic encoding process is started immediately after the initialization notification signal 211 is input.

The audio encoding unit 200 outputs the initialization notification signal 2
At the time of input of 11, an audio encoding process is initialized, and after this initialization, an audio encoded signal 210 is created by encoding the input audio signal 110.

The multiplexing unit 202 outputs the coded audio signal 210
Multiplex the initialization notification signal 211 and output signal 111
Is created and output to the first wireless terminal 102.

The first wireless terminal 102 transmits a transmission signal 113 to the second wireless terminal 104 via the transmission path 103.

The second wireless terminal 104 transmits the transmission signal 113
Is converted into an input signal 114 and output to the separation unit 300 in the audio decoding device 105.

The separating section 300 separates the input signal 114 into the received audio coded signal 310 and the reception initialization notification signal 311. The audio decoding unit 301 receives the reception initialization notification signal 3
11, the audio decoding process is initialized irrespective of the operation status, and thereafter, the received audio encoded signal 310 is decoded to create and output the decoded audio signal 115.

As described above, according to the audio signal distribution system 100 of the first embodiment, after confirming the call connection after the incoming call to the first wireless terminal 102, the encoding process of the audio encoding device 101 is initialized. After that, the input audio signal 110 is encoded,
This acoustic coded signal is multiplexed with the initialized signal subjected to the above-described initialization, and the multiplexed signal is multiplexed to the first wireless terminal 102.
The receiving multiplexed signal is received by the second wireless terminal 104 on the calling side connected to the call, and the received multiplexed signal is separated into an audio coded signal and an initialization signal by the audio decoding device 105. , The decoding process is initialized at the time of input, and then the audio coded signal is decoded to obtain the audio signal 115.

As a result, the audio decoding apparatus 105 is initialized with the signal that has been initialized by the audio encoding apparatus 101, so that no error occurs in the initial state of both apparatuses 101 and 105. As a result, the encoded audio signal transmitted from the transmitting side can be decoded on the receiving side to properly obtain the same acoustic signal as that on the transmitting side. As a result, the sound quality of the decoded audio signal can be improved on the receiving side.

(Embodiment 2) FIG. 4 is a block diagram showing a configuration of an audio encoding apparatus used in an audio signal distribution system according to Embodiment 2 of the present invention. However, in FIG. 4, portions corresponding to the respective portions in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The acoustic encoding device 401 shown in FIG.
In addition to the components shown in FIG.
2, an abnormal sound detecting unit 403, and an abnormal sound removing unit 404.

The local decoding unit 402 creates a local decoded audio signal 410 by decoding the audio encoded signal 210.

The abnormal sound detection section 403 detects abnormal sounds included in the local decoded sound signal 410 and outputs an abnormal sound detection signal 411 indicating the location of the detected abnormal sound.

The abnormal sound removing unit 404 outputs the sound encoded signal 21
A signal at an abnormal sound location indicated by an abnormal sound detection signal 411 at 0 is processed so as not to generate an abnormal sound, and a processed acoustic coded signal 412 obtained thereby is output.

Here, the multiplexing unit 202 multiplexes the processed audio coded signal 412 and the initialization notification signal 211,
An output signal 111 is created.

The operation of the audio encoding apparatus 401 having such a configuration will be described.

First, the audio encoding unit 200 creates an audio encoded signal 210 from the input audio signal 110 and outputs it to the local decoding unit 402 and the abnormal noise removing unit 404. The local decoding unit 402 outputs the audio encoded signal 210
Is decoded once to generate a local decoded sound signal 410 and output it to the abnormal sound detection unit 403.

The abnormal sound detecting section 403 checks whether or not the local decoded sound signal 410 includes an obviously abnormal music signal. Here, the apparently abnormal music signal is
For example, it indicates that a pulse-like sample having a short value and a large numerical value appears locally. When the abnormal sound detecting unit 403 detects an abnormal music signal, the abnormal sound detecting unit 403 outputs the abnormal sound detecting signal 411 to the abnormal sound removing unit 404, assuming that there is abnormal sound.

The abnormal sound removing unit 404 is adapted to output the audio encoded signal 21
If the abnormal sound detection signal 411 is not input, the audio encoded signal 210 is output as it is as the processed audio encoded signal 412, and if the abnormal sound detection signal 411 is input, the abnormal sound detection signal 411 is output. Is processed so that no abnormal sound is generated, and a processed acoustic coded signal 412 obtained by the processing is output.

As a processing method, for example, an abnormal sound portion is replaced with a silent parameter. Or audio coded signal 2
It is conceivable that the power information of No. 10 is changed so that the amplitude becomes small, so that abnormal noise hardly appears.

Then, the multiplexing section 202 multiplexes the processed sound coded signal 412 and the initialization notification signal 211 and outputs an output signal 111.

As described above, according to the audio coding apparatus 401 of the second embodiment, the local decoding section 402 decodes the audio coded signal 210 from the audio coding section 200 and the abnormal sound detecting section 403 outputs An abnormal sound included in the decoded local decoded sound signal 410 is detected, and an abnormal sound detection signal 411 indicating the detected abnormal sound is output. The abnormal sound indicated by the sound detection signal 411 is removed, and the
Then, since the processed sound coded signal 412 from which the abnormal noise has been removed and the initialization notification signal 211 are multiplexed,
On the receiving side, it is possible to reduce the occurrence rate of abnormal noise in the decoded audio signal.

(Embodiment 3) FIG. 5 is a block diagram showing a configuration of an audio signal distribution system according to Embodiment 3 of the present invention. The acoustic signal distribution system 50 shown in FIG.
0 is operated, for example, as a music distribution system.

The audio signal distribution system 500 has a function of transmitting and receiving a plurality of wireless terminals with the first wireless terminal 102 to which the audio coding apparatus 101 described in the first embodiment is connected or built. And an audio decoding device 5 for each
The configuration is such that encoded audio signals are distributed to third to fifth wireless terminals 501 to 503 to which the 04 to 506 are connected or built.

The acoustic signal distribution system 5 having such a configuration
00 will be described.

First, one third terminal is connected to the first wireless terminal 102.
When the wireless terminal 501 is call-connected, the same operation as described in the first embodiment is performed.

In this state, if another fourth wireless terminal 502 calls the first wireless terminal 102, the first wireless terminal 102 transmits the incoming call signal 112 to the audio encoding device 101. In response to this, the audio encoding device 101 initializes the audio encoding process, and outputs an initialization notification signal 211 to the multiplexing unit 202, so that the audio encoding device 101 communicates with the third wireless terminal 501 that has been call-connected. The transmission signal 113 multiplexed with the initialization notification signal is transmitted to the fourth wireless terminal 502 newly connected to the call.

Each of the wireless terminals 501 and 502 converts the transmission signal 113 into each of the input signals 510 and 512 and outputs the signals to the demultiplexing unit 300 in each of the audio decoding devices 504 and 505.

As a result, the separation unit 300 of each of the audio decoding devices 504 and 505 separates the input signal 114 into the received audio coded signal 310 and the reception initialization notification signal 311, and the audio decoding of each of the devices 504 and 505. The unit 301 is
Upon receiving the reception initialization notification signal 311, the audio decoding process is initialized regardless of the operation state, and thereafter, the decoded audio signals 511 and 513 are created by decoding the received audio coded signal 310. And output.

As described above, according to the audio signal distribution system 500 of the third embodiment, the first wireless terminal 102 has a function of transmitting and receiving to and from a plurality of other wireless terminals 501 to 503, and a plurality of wireless terminals Each time a call connection by an incoming call from each of the terminals 501 to 503 is executed in the first wireless terminal 102, the audio encoding device 101 initializes the encoding process, and the multiplexing in which the initialization notification signal is multiplexed. After the signal is received by each of the call-connected wireless terminals (for example, 501 and 502), the signals are separated by acoustic decoding devices 504 and 505 connected to the respective wireless terminals 501 and 502, and the separated signals are received. Since the decoding process is initialized by the initialization notification signal, even when one audio encoding device 101 and a plurality of audio decoding devices 504 to 506 are connected, the audio encoding device 101 Since each sound decoding apparatus 504 to 506 are initialized by a signal subjected to synchronize both the device 10
No error occurs in the initial state of 504 and 504 to 506. As a result, the audio coded signal transmitted from the transmitting side is decoded by a plurality of receiving sides, and the same acoustic signal as the transmitting side is appropriately reproduced. Obtainable. As a result, it is possible to improve the sound quality of the decoded sound signal on the plurality of receiving sides.

(Embodiment 4) FIG. 6 is a block diagram showing a configuration of an audio decoding apparatus used in an audio signal distribution system according to Embodiment 4 of the present invention. In FIG. 6, portions corresponding to the respective portions in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

The audio decoding apparatus 601 shown in FIG.
In addition to the components shown in FIG. 3, an incoming call notification unit 602 and an audio signal mixing unit 603 are provided.

The incoming call notifying section 602 outputs an incoming message signal 611 when the incoming call notifying signal 610 is detected while receiving the received audio coded signal 310.

The sound signal mixing section 603 mixes the decoded sound signal 115 and the incoming message signal 611, and outputs a mixed decoded sound signal 612.

The operation of the audio decoding apparatus 601 having such a configuration will be described.

[0086] Separation section 300 creates received audio coded signal 310 and reception initialization notification signal 311 from input signal 114. The audio decoding unit 301 decodes the received audio coded signal 310, creates a decoded audio signal 115, and outputs the decoded audio signal 115 to the audio signal mixing unit 603.

When the audio decoding unit 301 receives the reception initialization notification signal 311, the audio decoding unit 301 initializes the audio decoding process regardless of the operation status.

The incoming notification unit 602 outputs an incoming message signal 611 to the audio signal mixing unit 603 when an incoming notification signal 610 indicating that there is an incoming call from another is input.

Acoustic signal mixing section 603 mixes decoded audio signal 115 and incoming message signal 611 at an appropriate ratio, and outputs mixed decoded audio signal 612 multiplied by a gain so as to have an appropriate volume. I do.

As described above, according to the audio decoding apparatus 601 of the embodiment, when there is an incoming call request from another wireless terminal while receiving the received audio encoded signal 310, the incoming call notifying section 602 Then, an incoming message signal 611 is generated, and the audio signal mixing section 603 mixes and outputs the audio signal 115 decoded by the audio encoding section 301 and the incoming message signal 611. Even when decryption is being performed, it is possible to confirm that there is an incoming call from another wireless terminal, and as a result, the convenience when communicating with another person is improved.

[0082]

As described above, according to the present invention,
The encoded sound signal transmitted from the transmitting side can be decoded on the receiving side to properly obtain the same acoustic signal as that on the transmitting side.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an audio signal distribution system according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of an audio encoding device of the audio signal distribution system according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of an audio decoding device of the audio signal distribution system according to the first embodiment.

FIG. 4 is a block diagram showing a configuration of an audio encoding device used in an audio signal distribution system according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram showing a configuration of an audio signal distribution system according to Embodiment 3 of the present invention.

FIG. 6 is a block diagram showing a configuration of an audio decoding device used in an audio signal distribution system according to Embodiment 4 of the present invention.

FIG. 7 is a block diagram showing a configuration of a conventional audio signal distribution system.

FIG. 8 is a block diagram illustrating a configuration of an audio encoding device of a conventional audio signal distribution system.

FIG. 9 is a block diagram illustrating a configuration of an audio decoding device of a conventional audio signal distribution system.

[Explanation of symbols]

 100, 500 Acoustic signal distribution system 101, 401 Acoustic encoder 102 First wireless terminal 104 Second wireless terminal 105, 504 to 506, 601 Acoustic decoder 200 Acoustic encoder 201 Call connection checker 202 Multiplexing Unit 300 separation unit 301 sound decoding unit 402 local decoding unit 403 abnormal sound detection unit 404 abnormal sound removal unit 501 to 503 third to fifth wireless terminals 602 incoming call notification unit 603 sound signal mixing unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D045 AB26 DA20 5K067 AA23 AA33 DD54 EE02 FF25 GG01 GG11 HH21 9A001 CC05 CC06 EE02 EE04 EE05 HH15 JJ12 KK31

Claims (7)

[Claims] A first wireless terminal for wirelessly transmitting / receiving a signal; and a call connection confirming means for outputting an initialization notification signal when confirming a call connection after receiving a call to the first wireless terminal; Encoding means for initializing the encoding process at the time of inputting the initialization notification signal and then encoding the audio signal to create an audio encoded signal; multiplexing the audio encoded signal and the initialization notification signal; An audio encoding device having multiplexing means for outputting a signal to the first wireless terminal; a second wireless terminal on the calling side connected to the first wireless terminal; and a second wireless terminal Separating means for separating the multiplexed signal received in the audio encoded signal and the initialization notification signal,
An audio decoding device comprising decoding means for initializing a decoding process at the time of inputting the separated initialization notification signal and thereafter decoding the separated audio encoded signal to obtain the audio signal. A sound signal distribution system characterized by the above-mentioned. 2. An audio encoding apparatus, comprising: a second decoding unit that decodes an encoded audio signal from an encoding unit; and an abnormal sound included in the decoded signal, and the detected abnormal sound is detected. Detecting means for outputting an abnormal sound detection signal indicating an abnormal sound; and removing means for removing the abnormal sound indicated by the abnormal sound detection signal in the audio coded signal, wherein the multiplexing means removes the abnormal sound. 2. The audio signal distribution system according to claim 1, wherein the encoded audio signal and the initialization notification signal are multiplexed. 3. The first wireless terminal has a function of transmitting and receiving to and from another plurality of second wireless terminals, and a call connection by an incoming call from each of the plurality of second wireless terminals is established by the first wireless terminal. The encoding process is initialized by the audio encoding device every time the device is executed, and a multiplexed signal obtained by multiplexing the initialization notification signal is
After the call is received by each of the connected second wireless terminals,
3. The apparatus according to claim 1, wherein the audio signal is separated by an audio decoding device connected to each of the second wireless terminals, and decoding processing is initialized by the separated initialization notification signal. Sound signal distribution system. 4. An audio decoding device, comprising: an incoming call notifying unit for generating an incoming message signal when an incoming call request is received from another wireless terminal while receiving an audio encoded signal; The audio signal distribution system according to any one of claims 1 to 3, further comprising mixing means for mixing and outputting the converted audio signal and the incoming message signal. 5. The audio coding device is connected to or built into the first wireless terminal, and the audio decoding device is connected or built into the second wireless terminal. The acoustic signal distribution system according to any one of the above. 6. A mobile communication system comprising the audio signal distribution system according to claim 1. 7. After confirming a call connection after receiving a call to the wireless terminal, an audio signal is encoded after initializing an encoding process of an audio encoding device, and the initialization is performed with the audio encoded signal. The initialization signal is multiplexed, and the multiplexed signal is received by a calling-side wireless terminal that is call-connected to the wireless terminal,
The received multiplexed signal is separated into the audio coded signal and the initialization signal by an audio decoding device, and the separated audio coded signal is initialized after the decoding process is initialized by the separated initialization signal. An audio signal distribution method characterized by obtaining an audio signal by decoding.