JPH08107375A - Sound signal recording and reproducing device - Google Patents

Abstract

PURPOSE: To receive a sound without reception of the effect of a reproduced sound when a sound is picked up from a microphone while reproducing the sound from a speaker by providing an echo canceller between an A/D converter, a D/A converter connecting respectively to the microphone and the speaker and the sound signal recording and reproducing device. CONSTITUTION: A sound signal reproduction section 8 reads data of a reproduction sound stored on a recording medium and sends them to an echo canceller 1 at a prescribed interval each. Then data of the reproduced sound given to a D/A converter 2 are converted therein into an analog signal and amplified by an amplifier 3 and sounded from a speaker 4. Then a sound signal given to the microphone is amplified by an amplifier 6 and converted into a digital signal by an A/D converter 7 and received by the echo canceller 1. The echo canceller 1 erases a signal resulting from the reproduction signal turned around the speaker 4 among the received signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal recording / reproducing apparatus, a video camera and a television receiver having an audio signal input / output function.

[0002]

2. Description of the Related Art In a conventional acoustic signal recording / reproducing apparatus having an acoustic signal input / output function, signal acquisition and reproduction are not performed simultaneously as separate processes.

For example, a digital audio tape recorder (hereinafter referred to as "DAT") is known as one of the devices having an input / output function of an acoustic signal (Japanese Patent Laid-Open No. 2-23).
(574 publication). The DAT has a structure as shown in FIG.

That is, DAT is a microphone, a speaker,
It has a low-pass filter (LPF), an A / D converter, a D / A converter, and a signal processing circuit, and has a function of reproducing and taking in an acoustic signal such as a voice signal or a musical sound with a digital signal.

In DAT, when recording an acoustic signal, first, a 1-channel or 2-channel acoustic signal picked up by a microphone is converted into a PCM signal by an A / D converter through a low-pass filter. In the digital signal processing circuit, an error correction code is added, a predetermined modulation is performed, and the data is recorded via a predetermined path.

On the other hand, at the time of reproduction, the digital signal reproduced from the recorded magnetic tape is subjected to data demodulation, error detection and correction, etc. in the signal processing circuit. Then D
The signal is converted into an analog signal by the / A converter, passed through the LPF, and output as an acoustic signal by the speaker.

As described above, the acoustic signal and the audio signal in the DAT are reproduced and taken in, but the arrangement is such that the signal taking-in and the reproduction are not performed simultaneously as separate processes. Although DAT has been taken up as an example of the audio signal recording / reproducing apparatus, in the other audio signal recording / reproducing apparatuses, the signal acquisition and the reproduction are not simultaneously performed as separate processes.

Also in the video camera, the acquisition and reproduction of the audio signal together with the video signal are not performed as separate processes at the same time. In a television receiver, the audio signal is reproduced only and is not generally captured.

[0009]

According to the audio signal recording / reproducing apparatus of the above-mentioned prior art, since the microphone and the speaker are arranged in the same housing or relatively close to each other, the sound is reproduced by the speaker. When the sound is taken in from the microphone, there is a problem that the sound reproduced from the speaker wraps around the microphone and is buried. Furthermore, when voice recognition or the like is performed using this voice signal, there are drawbacks such that recognition is not performed or erroneous recognition occurs.

Similar problems and drawbacks also occur when a video camera and a television receiver simultaneously capture and reproduce audio signals.

An object of the present invention is, in an audio signal recording / reproducing apparatus, a video camera, or a television receiver, when the sound is taken in from the microphone while reproducing the sound from the speaker, it is not affected by the sound being reproduced. It is to provide a device capable of capturing sound.

[0012]

The above object is to provide an A / D converter connected to a microphone and a speaker via an amplifier, and an echo canceller between the D / A converter and the audio signal recording / reproducing apparatus. Will be solved by.

[0013]

When the sound is taken in from the microphone while reproducing the sound from the speaker, the echo canceller performs an operation of canceling the signal sneaking into the microphone from the speaker. Therefore, the input signal of the microphone that has passed through the echo canceller is not affected by the sound reproduced from the speaker.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In each embodiment, the same parts are designated by the same reference numerals, and duplicate description will be omitted unless particularly necessary.

First, the operation of the echo canceller will be described until the embodiment is entered. As a known example of the echo canceller, there is JP-A-62-123837. FIG. 3 is a block diagram showing the configuration of the echo canceller.

In FIG. 3, 1 is an echo canceller, 21
Is a first input terminal, 22 is an X register capable of sequentially storing n sample values, 23 is a first output register, 24 is a second input terminal, 25 is a subtracter, and 26 is a second
, 27 is a convolutional integrator, 28 is a tap coefficient register for storing n signals, 29 is a correction amount calculator,
30 is an adder.

The reproduced signal is input from the first input terminal 21 of the echo canceller 1, input to the X register 22 and output from the first output terminal 23. on the other hand,
The input signal from the microphone is input from the second input terminal 24, passes through the subtractor 25, and is output from the second output terminal 26.

The reproduction signal input to the X register 22 is 1
N samples are sequentially stored for each sample. The X register 22 is configured as a shift register, and moves to the adjacent one for each sample. And the data in the last position is discarded. As a result, the latest n samples of reproduced signal data are always stored.

The tap coefficient register 28 is an X register 22.
The tap coefficient, which is an approximation of the impulse response of the echo path to be estimated, is stored in the same number as n registers.

The convolutional integrator 27 uses the tap coefficient register 28 and n pieces of data of the X register 22 as input signals to perform convolutional integration.

That is, let n tap coefficient registers be h
(N), (n = 0,1,2 ... n-1), n X registers are X (n), (n = 0,1,2 ... n-1),
When the pseudo echo signal is y (t), the pseudo echo signal y (t) is calculated by the following formula.

[0022]

[Equation 1]

The subtractor 25 subtracts the pseudo echo signal from the input signal and outputs the result from the second output terminal 26.
Let this signal be e (t), and let m be the input signal from the microphone.
Let (t) be expressed by the following equation.

[0024]

[Equation 2]

That is, this signal e (t) is the echo signal canceled.

Next, a method of calculating the tap coefficient stored in the tap coefficient register 28 will be described.

When the reproduced sound from the speaker is output in a sufficient magnitude and the signal input from the microphone is only the reproduced sound, the output result of the subtractor 25 becomes an arithmetic error. That is, this calculation result is caused by the estimation error of the estimation signal. This means that the tap coefficient does not match the characteristics of the echo path. The correction amount calculator 29 calculates the correction amount of the tap coefficient from the estimated error signal and the reproduction signal stored in the X register. The LMS method (least mean square method, Least Mean Square M
There is a well-known algorithm such as the method) or the learning identification method. This is a method in which tap coefficients are successively corrected based on e (t) and x (t) and the corrections are given as tap coefficients.

When this is expressed by an equation, n tap coefficients are hi
(T), the correction amount of the tap coefficient is Δhi (t), (i =
0, 1, 2, ..., N-1) is as follows.

[0029]

(Equation 3)

[0030]

[Equation 4]

Here, G is a correction coefficient, which is a constant in the LMS method. The learning identification method is given by the following equation.

[0032]

(Equation 5)

That is, the calculated correction amount is obtained by reading the tap coefficient stored in the tap coefficient register 28 and adding it with the correction amount in the adder 30. This is stored in the tap coefficient register as a new tap coefficient.

In practice, these equations operate so that the above-mentioned estimation error signal becomes zero. These updating operations are performed when the signal taken in from the microphone is only the signal reproduced from the speaker. When other signals are mixed, the estimation error signal is not caused only by the deviation of the tap coefficient, and the arithmetic operations of the equations 3 and 4 for making the estimation error signal 0 make the tap coefficient an incorrect value. It will be fixed. Therefore, these updating operations are performed when other signals are not mixed. As an example of the detection means in that case, it can be realized by comparing the level of the reproduction signal with the level of the input signal from the microphone. As a result, the operation of the echo canceller can be stably performed.

The operation of the echo canceller has been described above.

Next, a detailed description of the embodiment of the present invention will be given with reference to FIG. FIG. 1 shows the configuration of the first embodiment of the present invention. 1 is an echo canceller, 2 is a D / A converter, 3 is an amplifier, 4 is a speaker, 5 is a microphone, 6 is an amplifier, and 7 is A.
A / D converter, 8 is an acoustic signal reproducing unit, 9 is an acoustic signal recording unit, and 10 is an acoustic signal recording / reproducing unit.

In the acoustic signal reproducing section 8, reproduced sound data stored in a recording medium such as a magnetic tape, an optical disk or a memory is read out and subjected to predetermined signal processing, and then the echo canceller 1 is arranged at regular intervals. To the first input terminal of the. The echo canceller 1 sends this signal from the first output terminal to the D / A converter 2, and
As mentioned above, it produces a pseudo echo signal. On the other hand, D /
The reproduced sound data input to the A converter 2 is converted into analog signals one after another here, amplified appropriately by the amplifier 3, and then reproduced from the speaker 4.

Next, the acoustic signal input from the microphone 5 is converted into an electric signal here and is appropriately amplified in the amplifier 6, and then converted into a digital signal in the A / D converter 7 one after another, and then in the echo canceller 1. It is captured.

In the echo canceller 1, as described above, the signal in which the reproduction signal wraps around through the speaker is deleted from this signal. Therefore, the remaining signal is the signal from the microphone excluding the signal from the speaker. This signal is output from the second output terminal.

The signal output from the second output terminal of the echo canceller 1 is subjected to predetermined signal processing in the acoustic signal recording section 9 and then recorded on the recording medium.

According to this embodiment, while reproducing the sound from the speaker, the echo canceller is used to cancel the influence of the reproduced sound from the signal input from the microphone, and the target sound such as ambient sound or voice is taken in. be able to.

If the desired sound cannot be obtained clearly, such as when shooting in a room with a long reverberation time, it may be due to the difference in the recording location.
The echo canceller is particularly effective when it is desired to remove the influence of the reproduced sound.

An example of using the system of this embodiment will be described in the case of a karaoke apparatus having a recording function. A song is sung according to the music (accompaniment) reproduced from the speaker of the karaoke apparatus, the reproduced sound is removed by the echo canceller, and only the singing person's song (voice) is recorded. Later, if you listen to only your own recorded song without accompaniment, the difference from the original song will be clear, so it can be used for karaoke practice. In addition, you can analyze the song recorded later, synthesize it with other music, and adjust the level freely, so you can enjoy various editing.

Another example of use is when the system of this embodiment is used during an interview. There is a case in which a question or a sound that has already been stored is reproduced by an acoustic signal recording / reproducing device and only a response to the question or the sound is desired to be recorded. In such cases, we want the response to be cleanly separated from the question and recorded clearly. The recording / reproducing apparatus using the echo canceller has the effect of clearly recording only the target sound even if the reproduced sound is large. Also, at this time, it is possible to play and record at the same time, and even if the listener hears a response and makes a sound in the middle of the sound, the response is not buried in the reproduced sound. Only can be recorded.

Here, when it is desired to record the reproduced sound at the same time, an application such as a switch may be considered so that the operation of the echo canceller is stopped and the sound taken from the microphone is recorded as it is.

As a second embodiment of the present invention, an example relating to a video camera will be described with reference to FIG. 31 is a display device, 32 is an image pickup device, 33 is a video camera signal reproduction unit,
34 is a video camera signal recording unit, 35 is an audio signal reproducing circuit, 36 is a video signal reproducing circuit, 37 is an audio signal recording circuit, 38 is a video signal recording circuit, 39 is a signal reproducing mechanism, 4
0 is a signal recording mechanism.

The signal stored in a recording medium such as a magnetic tape is read by the signal reproduction mechanism 39 of the video camera signal reproduction unit 33, of which the audio signal is reproduced by the acoustic signal reproduction circuit 35 and the video signal is reproduced by the video signal. Sent to circuit 36. The video signal is processed by the video reproduction circuit 36, and the video is displayed on the display device 31 such as a liquid crystal panel.

On the other hand, the acoustic signal is sent to the first input terminal of the echo canceller 1 at regular intervals after being subjected to predetermined signal processing in the acoustic signal reproducing circuit 35. The echo canceller 1 sends this signal from the first output terminal to the D / A converter 2, and at the same time produces the pseudo echo signal as mentioned above. On the other hand, the reproduced sound data input to the D / A converter 2 is converted into analog signals one after another here, and the amplifier 3
After being appropriately amplified by, the sound is reproduced from the speaker 4.

Next, the operation of the recording system will be described. The video signal obtained by imaging the subject with the imaging device 32 is
After being supplied to the video signal recording circuit 38 and subjected to processing for recording, the recording mechanism section 40 records it on a recording medium such as a magnetic tape.

The acoustic signal input from the microphone 5 is converted into an electric signal here and is appropriately amplified in the amplifier 6, and then converted into a digital signal one after another in the A / D converter 7 and taken into the echo canceller 1. Be done.

As described above, the echo canceller 1 eliminates the signal in which the reproduction signal has passed through the speaker from this signal. Therefore, the remaining signal is the signal from the microphone excluding the signal from the speaker. This signal is output from the second output terminal.

The signal output from the second output terminal of the echo canceller 1 is recorded on the recording medium after being subjected to predetermined signal processing in the acoustic signal recording section.

Although the signal recording unit and the signal reproducing unit are separately provided in FIGS. 1 and 2, if the signal recording / reproducing mechanism is capable of recording and reproducing signals in parallel in a time-division manner or the like, The signal recording medium and the signal reproducing medium may be one.

Here, by providing the audio signal output means in the video camera, it is possible to shoot while playing BGM (BackGround Musisc), and to play effective sound for shooting or play relaxing music. We can provide a video camera that can shoot in a variety of different sound environments. Further, by providing the echo canceller, it is possible to record the sound in which the BGM is canceled out of the signal input from the microphone even when the BGM is flowing.

The effect of providing the echo canceller, the sound signal reproducing means, and the image reproducing means separately in the video camera and the viewfinder for displaying the image being recorded is as an effect. Is recorded and the response and the response to it are reproduced. At this time, the reaction or response sound can be recorded without being buried in the reproduced sound. The effect is that even if the reproduced sound is loud, the reaction and sound can be clearly incorporated. Further, when the image and the sound at the time of reproduction and the image and the sound which are the reactions thereof are later watched together, the level adjustment can be performed separately for the reproduced sound and the reacted sound, and both can be clearly presented.

Further, as an effect of the present embodiment, for example, a certain original image and sound which have already been recorded are reproduced and presented to a certain person A. Next, at the same time as the reproduction, the reaction of the person A to the displayed image and sound is recorded and recorded. Then, when performing a quiz to which the information reproduced first is applied from the recorded video and audio information, the information reproduced first needs to be removed and recorded.
The reproduced video does not remain in the recording, but the reproduced sound is recorded because it goes into the microphone. In such cases,
Use the echo canceller to remove the reproduced sound and record.

When it is not necessary to reproduce the image on the display device of the video camera, the same image as the image being recorded from the camera (the image seen by the operator) is displayed on the image display section, A person who is symmetrical to the subject can be considered to have another usage, such as taking a picture while checking the appearance of the person at any time.

According to the first and second embodiments, there is an effect that the desired sound can be taken in from the microphone without being affected by the sound even when the sound is being emitted from the speaker.

An example using voice recognition will be described as the third embodiment.

First, the voice recognition process will be described with reference to FIG. FIG. 5 is a flowchart showing the procedure of the voice recognition process.

First, audio signals are sequentially taken in. (Step 1) A characteristic parameter for a fixed period is extracted from the captured audio signal. (Step 2) The captured voice signal or its characteristic parameters are monitored for a certain period of time, and the voice is cut out. (Step 3) For example, the magnitude of the voice signal taken in is monitored, and if a signal that continues for a certain period comes, it is determined that a word of voice is input in that section, and the process proceeds to the next step. Otherwise, it returns to the voice input process again.

Next, the similarity is calculated between the characteristic parameter of this section and the characteristic parameter of the word registered in advance. (Step 4) At this time, in order to reduce the influence of the difference in the utterance speed even for the same word, for example, a method such as DP matching that absorbs the difference in the utterance speed is generally used.

If the calculated similarity of the characteristic parameters is larger than a certain value, it is judged that the input word is voice registered in advance, that is, voice recognition is performed. If the degree of similarity is smaller than a certain value, it is determined that the input voice is different from the registered voice, and the voice input process is performed again. (Step 5) When the input voice is recognized, the process at the time of recognition is performed next. (Step 6) Next, an embodiment in which the output of the echo canceller is used for the voice recognition processing will be described with reference to FIG. 6 in the case of a television receiver.

In FIG. 6, reference numeral 51 is a voice recognition circuit, 52 is a television receiving circuit, 53 is an antenna, and 54 is a display device.

The television receiving circuit 52 receives the broadcast wave transmitted from the broadcasting station, and the obtained image signal is subjected to predetermined processing and displayed on the display device 54.

At the same time, the audio signal transmitted from the broadcasting station is sent to the first input terminal of the echo canceller 1 at regular intervals after being subjected to predetermined signal processing. The echo canceller 1 sends this signal from the first output terminal to the D / A converter 2, and at the same time produces the pseudo echo signal as mentioned above. On the other hand, the reproduced sound data input to the D / A converter 2 are converted into analog signals one after another here, amplified appropriately by the amplifier 3, and then reproduced from the speaker 4.

On the other hand, the acoustic signal input from the microphone 5 is converted into an electric signal here and is appropriately amplified in the amplifier 6, and then converted into a digital signal one after another in the A / D converter 7 and taken into the echo canceller 1. Be done.

As described above, the echo canceller 1 eliminates the signal in which the reproduction signal has passed through the speaker from this signal. Therefore, the remaining signal is the signal from the microphone excluding the signal from the speaker. This signal is output from the second output terminal. The output is supplied to the voice recognition circuit 51, and voice recognition is performed according to the flow of the processing described above. The result of recognition is output to the television receiving circuit 52, and the process according to the result of recognition is performed.

In the present embodiment, the case of the television receiver has been described, but also in the acoustic signal recording / reproducing apparatus, for example, the output of the second output terminal of the echo canceller 1 in FIG. Output of speech recognition circuit,
That is, by adopting a configuration in which the recognition result is input to the acoustic signal recording / reproducing apparatus, it is possible to perform the processing by voice recognition after removing the influence of the reproduced sound by using the echo canceller.

Similarly, in the video camera, the output of the second output terminal of the echo canceller 1 is input to the voice recognition circuit in FIG. 3, and the output of the voice recognition circuit, that is, the recognition result is input to the video camera. By
It is possible to perform processing by voice recognition after removing the influence of reproduced sound by using an echo canceller.

As the processing at the time of voice recognition, for example, a person around the apparatus such as an operator recognizes the voice uttered,
In response to this, the volume of the reproduced sound is changed and the operation of the device is controlled. Device operation control includes, for example, starting, stopping, and pausing recording or playback of music or video, fast-forwarding and rewinding recording media such as magnetic tape, and changing the output sound level. Or
It is to change the brightness and contrast of the display device, to switch channels in the case of a television receiver, and to control various functions of other devices.

Further, a command for giving some kind of image display or a change in the displayed image is sent to the display control circuit, and the display device makes a display corresponding to it. For example, when recognition is performed, a new image appears in the displayed image or the color or shape of the displayed image changes when the recognition is performed.

Further, not only the change of the displayed image but also the sound to be reproduced next can be changed. That is, when voice recognition is performed, it may be possible to give a specific sound to the operator or change the tone color of the sound being reproduced.

The simple example of the voice recognition process has been described above with reference to FIGS. In the above embodiment, the recognition of one word is taken up, but in the recognition of a plurality of words, the similarity calculation unit (step 4 in FIG. 5) calculates the similarity with the characteristic parameters of a plurality of voices registered in advance. It is possible to recognize a plurality of words by calculating respectively. After that, the voice recognition process of a plurality of voices can be performed by performing each process according to the recognized word.

According to this embodiment, even when a sound is being emitted from the speaker, it is not affected by the sound,
There is an effect that the control operation is accurately performed according to the uttered voice.

A fourth embodiment will be described with reference to FIG. 7 in interactive television broadcasting and video games.
Known examples of interactive television broadcasting and video games include:
There are JP-A-63-23467 and JP-A-60-99283.

In the interactive television, the interactive television transmits the opinion of the viewer in real time to the broadcasting station and advances the broadcast program while incorporating the opinion. Here, it is assumed that audio is used as a means for the viewer to input a response.

In FIG. 7, reference numeral 55 is a control circuit, 56 is a transmission control circuit, and 57 is a transmission signal output terminal.

It is sent from the broadcasting station via broadcast waves,
A video signal and an audio signal of a television or a video game are received by the television receiver 52 via the antenna 53.

A control circuit 55 is connected to the television receiver 52. The control circuit 55 displays a superimpose display for prompting the viewer to input a response (viewer data),
The superimpose display related to the contents input by the viewer is displayed on the television receiver.

The viewer voices the display from the control circuit 55 and the response to the request. The sound picked up by the microphone 5 is canceled by the echo canceller 1 due to the output sound from the television receiving circuit 52. Then, the voice recognition circuit 51
Then, the word is recognized from the output from the echo canceller 1, and the identification code for the word is output to the transmission control circuit 56 as the recognition result. The transmission control circuit 55 outputs the identification code as viewer data (response) to a television station, a data collection station, a control station, or an opponent of a game through a telephone line or a wireless line according to a communication format. It transmits from the terminal 57.

As the response (data) of the viewer, for example, as a response to a quiz or question in the program, "Yes",
There are "No", the number of the selected branch, and various other words. In the case of a game, there are words corresponding to various operations during the game. The operation in this case includes, for example, changing the scenario in the progress of the game, adjusting the volume, and controlling the screen.

At this time, even when a sound such as a sound effect is played from the television side, the echo canceller extracts only the target sound and correctly recognizes it.

Further, even when a plurality of people such as family members use the same device to respond to an interactive television broadcast program, the voice speaker can be used without the troublesome operation of inputting an individual identification number or the like. There are examples of recognition.

According to this embodiment, even when a sound is being emitted from the speaker, it is not affected by the sound,
There is an effect that the voice uttered by the viewer is accurately recognized, and the interactive television and the video game can accurately react.

[0086]

According to the present invention, the target sound can be taken in from the microphone even while the sound is being reproduced from the speaker, and the sound sneaking into the microphone from the speaker can be erased. It is never buried in the reproduced sound. Therefore, it is possible to obtain the effect that the sound can be picked up by the microphone while being reproduced with a sound louder than the speaker.

As a second effect, since the voice recognition can be performed without being influenced by the sound effect, a great effect can be obtained in improving the recognition rate.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional example.

FIG. 3 is a block diagram showing an example of the configuration of an echo canceller.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a flow of voice recognition processing.

FIG. 6 is a block diagram showing a third embodiment of the present invention.

FIG. 7 is a block diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Echo canceller, 2 ... D / A converter, 3 ... Amplifier, 4 ... Speaker, 5 ... Microphone, 6 ... Amplifier, 7 ... A / D converter, 8 ... Acoustic signal reproducing part, 9 ... Acoustic signal recording part , 10 ... Acoustic signal recording / reproducing unit.

Claims (11)

[Claims] 1. A signal reflection path between a first output terminal and a second input signal terminal is adaptively estimated having first and second input terminals and first and second output terminals. An echo canceller for canceling a signal that has passed through the signal reflection path from a signal input to the second input terminal, an output terminal connected to a first input terminal of the echo canceller, and a second output of the echo canceller. An audio signal recording / reproducing apparatus having an input terminal connected to the output terminal of the. 2. The acoustic signal recording / reproducing apparatus according to claim 1, wherein the acoustic signal recording / reproducing apparatus is connected to a first input terminal of the echo canceller, and acoustic signal reproducing means for reproducing an acoustic signal, An acoustic signal recording / reproducing apparatus, which is connected to a second output terminal of the echo canceller, has acoustic signal recording means for recording an acoustic signal, and reproduces the acoustic signal and records the acoustic signal at the same time. 3. A signal reflection path between the first output terminal and the second input signal terminal is adaptively estimated having first and second input terminals and first and second output terminals. An echo canceller for canceling a signal that has passed through the signal reflection path from a signal input to the second input terminal, an output terminal connected to a first input terminal of the echo canceller, and a second output of the echo canceller. A video camera having an input terminal connected to the output terminal of the video camera. 4. The video camera according to claim 3, wherein
The video camera is connected to a first input terminal of the echo canceller to reproduce an acoustic signal, and is connected to a second output terminal of the echo canceller to record an acoustic signal. A video camera having means for reproducing an audio signal and recording the audio signal at the same time. 5. A signal reflection path between the first output terminal and the second input signal terminal is adaptively estimated having first and second input terminals and first and second output terminals. An echo canceller for canceling a signal that has passed through the signal reflection path from a signal input to the second input terminal, an output terminal connected to a first input terminal of the echo canceller, and a second output of the echo canceller. A television receiver having an input terminal connected to the output terminal of. 6. The television receiver according to claim 5,
The television receiver is connected to a first input terminal of the echo canceller and reproduces an acoustic signal, and an acoustic signal reproducing means for reproducing an acoustic signal, and an acoustic signal for recording an acoustic signal, which is connected to a second output terminal of the echo canceller. A television receiver having recording means for reproducing an audio signal and recording the audio signal at the same time. 7. An acoustic signal recording / reproducing apparatus, a video camera and a television receiver according to claim 1, 2, 3, 4, 5 or 6, further comprising an acoustic signal reproducing means, and a second output of the echo canceller. A sound signal control system for controlling the reproduced sound of the sound signal reproducing means according to the signal of. 8. An acoustic signal recording / reproducing apparatus, a video camera and a television receiver according to claim 1, 2, 3, 4, 5 or 6, further comprising image display means, and a second output of the echo canceller. An image control method for controlling a display image of the image display means according to the signal of. 9. An acoustic signal recording / reproducing device, a video camera and a television receiver according to claim 1, 2, 3, 4, 5 or 6, further comprising a voice recognizing means, and the second echo canceller is provided.
A voice recognition system characterized in that the signal of the output terminal of is used as an input signal of the voice recognition means. 10. The acoustic signal recording / reproducing device, video camera, and television receiver according to claim 1, 2, 3, 4, 5, or 6, wherein the acoustic signal recording / reproducing device, video camera, and television receiver. Each has a voice recognition means,
In the voice recognition means, the second of the echo canceller
An audio signal is recognized using the signal from the output terminal as an input signal, and the audio signal recording / reproducing device, the video camera, and the television receiver are operated based on the result of the audio recognition. 11. The television receiver according to claim 5 or 6, wherein the television receiver comprises a voice recognition means and a transmission means for transmitting a response of a viewer, and the voice recognition means comprises a first of the echo cancellers. A television receiver characterized in that voice recognition is performed by using a signal from an output terminal of 2 as an input signal, and the result is output by the transmitting means as a response of a viewer.