KR950000577B1 - Multi-channel sound recording device and method - Google Patents

Abstract

The apparatus used in the control rooms, such as an airport tower or army headquarters, for recording the various voice signals without intermittence and reproducing them after searching of high speed includes a circuit (1) inputting the voice signals, a modulator (2) converting the multiplied voice signal to the image signals, a demodulator (7) converting the reproduced image signals to the digital voice and time data, a CPU (5) controlling the modulator and demodulator, and a circuit (8) providing the voice after amplifying.

Description

Multichannel voice recording and playback device and method

1 is a block diagram of a multi-channel voice recorder according to the present invention.

2 is a schematic diagram according to the function of FIG.

3 is a block diagram of a signal input unit according to the present invention.

4 is a block diagram of a multiplexer unit according to the present invention.

5 is a block diagram of a demultiplexer unit according to the present invention.

6 is a block diagram of a D / A conversion unit according to the present invention.

7 is a block diagram of an I / O control unit according to the present invention.

8 is a block diagram of a central control unit according to the present invention.

9 is a multiplexing signal sequence diagram illustrating the concept according to the present invention.

10 is a waveform diagram of a multiplexed voice signal.

11 is a waveform diagram of an NTSC video signal.

12A, 12B, and 12C illustrate an industry standard VHS recording signal.

13 is a waveform diagram showing the relationship between the non-recording period of a continuous audio signal and a video signal.

14 is a diagram showing a recording principle and configuration of a conventional multi-channel analog signal.

* Explanation of symbols for main parts of the drawings

1: signal input 2: multiplexer

3: recording deck 4: I / O controller

5: central control unit 6: playback deck

7: Demultiplexer 8: Audio output

9: speaker 21: A / D conversion unit

22,73: memory 23: video signal generator

24: time data and control signal generating circuit

71: data recovery circuit 74: D / A conversion unit

72: data conversion and memory control circuit

The present invention relates to a multi-channel voice recording and reproducing apparatus and method thereof, and more particularly, to a long time continuous recording function, a simultaneous recording function of dozens of voice lines with one recorder, and a time recording search function for reproducing recorded contents at high speed. The present invention relates to a multichannel audio recording and reproducing apparatus provided therein and a method thereof.

There are analogue and digital expressions about recording editing reproduction. Analog type uses a continuous voice filter, so it has a simple function, but it takes a long time for continuous function and search. Digital expression has high degree of freedom of editing and searching, fast searching, and no deterioration of quality even for long-term use. It is desirable to use digital at the present time that the price of digital memory is low. In order to digitally record audio, waveform coding methods are used, such as pulse code modulation (PCM), adaptive differential PCM (ADPCM), and adaptive predictive coding (APC). However, the S / N ratio is a problem in such a digital system.

The multi-channel recorder according to the present invention without disconnection of the transaction control room of the airport control room, police command room, military operation control room, securities, financial institutions, futures market, and other wired and wireless communication contents for the purpose of managing wired and wireless communication without disconnection. It is a recorder for continuous recording, and it is a device for managing and supervising communication contents by simultaneously recording several voice signals.

In the case of the existing multichannel voice recorder, in order to record the multichannel signal while keeping the analog signal as usual, the multichannel special recorder has been recorded on a wide (1 inch or more) reel tape.

14 is a diagram illustrating a recording principle of a conventional multichannel analog signal. As shown in FIG. 4, since recording is performed on tracks corresponding to the number of channels following the direction of tape movement, the larger the number of tracks, the wider the width of the tape, and the header of the tracker according to the number of tracks. A special header for multichannels is required, which requires highly accumulated technology to eliminate the effects between tracks.

The price of such a reel tape is quite expensive, and also requires a very large place for storage. In addition, it must be rewound after recording to be stored, and there have been inconveniences such as requiring great care in handling the tape. Analog multi-channel special headers are also expensive parts that can be used only in multi-channel recorders, and at least two recorders (or even DECKs) are required for playback during recording or continuous recording. A lot of investment was needed.

Basically, due to the size of the reel tape (standard 8 or 10.5 inch diameter), the space required for office cabinets is required for the entire equipment installation, and a large space is required for storing and recording the recorded tape. Therefore, it is true that it is not easy to install because of economic and space problems even where multichannel recording is necessary.

Due to this inconvenience, a new type of multichannel voice recorder has been developed and sold by a few foreign famous manufacturers. Instead of a reel tape that is difficult to store and manage, it is a cassette tape recorder. The cassette tape used in this case generally uses the highest quality video cassette tape, which is 1) easier to obtain and cheaper than reel tape, 2) saves space for storage, and 3) records to the end of the tape. Not only can this be replaced with a new tape without the need for rewinding, but 4) the tape has been reduced in size, resulting in a smaller overall size of mercy.

However, because of the special cassette, the special motor control method, and the very complicated mechanical structure for recording the cassette tape for a long time, the price of the equipment itself is very expensive, and there is a problem of using the best video tape for the used tape.

Disclosure of Invention An object of the present invention is to solve the above problems, and to provide a multi-channel voice recording and reproducing apparatus and method thereof of cheaper and more reliable digital voice recording.

Another object of the present invention is to provide a multi-channel audio recording and reproducing apparatus and method for realizing a recording search function at high speed.

In order to achieve the above object, the multi-channel audio recording and reproducing apparatus according to the present invention converts the analog signal input from the signal input unit for inputting an external voice signal, the analog signal input from the signal input unit into digital data, and matches the standard signal NTSC signal. A multiplexer section (hereinafter referred to as the "MUX section") that generates vertical and horizontal sync signals, a recording deck for recording NTSC signals from the MUX section, a playback deck for playing back the recorded signal, and playback from the playback deck. I / O to control the recording and playback deck, the demultiplexer unit (hereinafter referred to as the "DEMUX unit"), the central control unit to control the MUX unit and the DEMUX unit, and the like. The control unit includes an audio output unit for amplifying the audio signal from the DEMUX unit and abnormality of the device itself and outputting the amplified sound to the speaker.

In addition, the signal input unit of the multi-channel audio recording and reproducing apparatus according to the present invention includes an automatic gain controller, an anti-aliasing filter, and a signal force detector for detecting a sound signal abnormality over the base noise. .

In addition, the MUX portion of the multi-channel audio recording and playback apparatus according to the present invention is a video signal generator for outputting an NTSC signal to a recording deck, and time data and control signals for controlling each circuit in the MUX portion according to a control signal from the central controller. It has a generation circuit.

In addition, the DEMUX section of the multi-channel audio recording and reproducing apparatus according to the present invention inputs an NTSC signal from the playback deck to generate an NRZ signal, a memory in the DEMUX and a D / A in accordance with a control signal from the central controller. A circuit for controlling the transducer.

The multi-channel voice recording and reproducing apparatus of the present invention converts the multi-channel input audio signal from the MUX unit into a digital signal and records it as a NTSC signal on the deck, and converts the recorded NTSC signal into an analog signal in the DEMUX unit if necessary. As a result, speed reduction can be achieved in miniaturization and retrieval of the apparatus. That is, according to the digital multichannel audio recording and reproducing apparatus of the present invention and the method thereof, in order to implement multi-channel simultaneous recording and high-speed time recording retrieval function at low cost and with high reliability, digital data multiplexed with a multi-channel analog audio signal It is then converted into a standard video signal with time data, which can be recorded and played back on VHS videotape and recording equipment.

Before describing specific embodiments of the present invention, the concept of the present invention will be described.

The audio signal has a bandwidth of about 3KHz from 300Hz to 3000Hz, whereas the video signal has a practical bandwidth from DC to 3.5MHz. Therefore, in the case of multiplexing the audio signal, it is theoretically more than hundreds of audio signals. However, due to the complexity and practicality of the modulator, it is possible to modulate dozens of audio signals and multiplex them into a video band signal. In fact, the PCM device, which is a voice multiplexing device in a long distance transmission section, is now digitally transmitting 1.544Mbps having a bandwidth of about 3MHz by multiplexing 24 voice signals.

In order to multiplex the audio signals, the audio signals of the entire line should be sampled at appropriate intervals. Multiplexed signals can be obtained by sampling the audio signals on each line at 7.2KHz, which is higher than 6.8KHz, which is twice the maximum band frequency of 3.4KHz, and arranging them sequentially as shown in FIGS. The sampling frequency of each line is 7.2KHz, but the signal period of the multiplexed signal is

7.2KHz X total number of lines (24 lines) = 172.8KHz (Equation 1)

This can be expressed as a rotary switch of 24 input contacts rotating 7200 times per second. In order to convert a multiplexed audio signal into a video signal, first convert the analog audio signal into a digital value, and then convert the converted data into a serial NRZ signal and load it appropriately in the area of the video signal (industrial standard NTSC waveform of FIG. 11). do.

As can be seen from FIG. 11 and FIG. 12, the NTSC video signal can not carry the audio signal in the vertical synchronization signal, the horizontal synchronization signal, the equalization pulse, the color burst board, and so on. If not recorded, discontinuities will occur for a short time, making it impossible to play practically.

However, as shown in FIG. 12, in the VHS method of recording in the industry table, signals between two vertical synchronous and vertical synchronous periods (one field signal) are recorded at an angle to one track in turn, which is 252.5 horizontal synchronous signals. And video signals. Basically, when recording, vertical and horizontal signals are detected and the recording and playback head is switched, tracking, and the servo control of the internal tape drive mechanism are used. To use the existing VHS type recorder, these signals are combined with multiplexed voice signals. Should be supplied.

In order to solve this problem, the present invention uses the following method. In other words, the multiplexed voice digital data, which has undergone the analog-to-digital (A / D) changer, is stored in a memory device and then compressed on the time axis to be converted into a video signal. As shown in FIG. 13, an audio signal of one field, which is 1/60 second, can be compressed on a time axis in correspondence to 240 effective video signal regions.

Thus, in order to convert the audio data for 1/60 seconds into a video signal of exactly one field, synchronization with the time of the vertical synchronization signal must be synchronized, and the audio data continuously input during the conversion to the video signal is simultaneously stored. It is necessary to bank switch the two memory blocks alternately. The size of one bank

172.8K (Equation 1) × 1/60 (One field time) = 2880Byte (Equation 2)

During storage of the first bank audio data, data stored in the second bank is converted into a video signal and synchronized with the next vertical synchronization. In the same way, the audio data compressed in the video signal can be extracted and stored in the memory bank, and then digital-analog (D / A) converted at the same frequency as the sampling frequency to restore the original audio signal.

Up to 24 voice lines can be accommodated in this way, and the number of time slots can actually be extended to 32 depending on the frequency characteristics of the video tape. You need to increase the memory and timing logic capacity accordingly.

When the audio data is modulated into a video signal, how the signal is configured is an important factor that greatly affects reliability. Twenty four digitalized voice data and time data consisting of year, month, day, hour, minute, and second are constructed as follows in consideration of the reliability within the frequency characteristics of the video tape. In other words, if the configuration of data for one line is set to Start bit 2 + Voice data 7 + Stop bit 1 = 10 bits in total (Equation 3), the dynamic range of the voice data becomes 42 dB. In addition, if one rasti period consists of 16 data, it is possible to guarantee sufficient reliability when reproducing and restoring data considering the frequency characteristics of the tape. In addition, synchronization bytes were added to the odd-numbered last of the raster and 6-byte time data was added to the even-last last so that the synchronization of each data bit and the order of each data byte could be found during playback. The video signal format configured in this manner is shown in FIG. The sync byte should be composed of all the time bits and all the remaining bits as low bits so that they do not overlap any channel data.

Odd numbered rasters: Sync byte 1 + voice data 1-15

Even numbered raster: Voice data No. 16-24 + Time data 6 bytes + Dummy bytes

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In addition, in all the drawings for demonstrating an embodiment, the thing with the same function uses the same code | symbol, and the repeated description is abbreviate | omitted.

1 is a configuration diagram of a multi-channel voice recorder according to the present invention, and FIG. 2 is a system diagram showing FIG.

1 and 2, the multi-channel voice recorder includes a signal input unit 1 for inputting an external analog voice signal, a MUX unit 2 for output multiplexing and digitally converting the signal input unit and then modulating it into an NTSC signal; Controlling the input and output of the recording deck 3 for recording NTSC signals output from the MUX section 2, the playback deck 6 for reproducing the recorded signal, the recording deck 3, and the playback deck 6 Central control unit for controlling the operation of the I / O control unit 4, the DEMUX unit 7 for demodulating the signal reproduced from the playback deck 6 to output the audio signal, the MUX unit 1 and the DEMUX unit ( 5) and an audio output unit 8 for outputting the demodulated signal from the DEMUX unit 7 to the speaker 9.

In the present invention, as shown in FIG. 1, the system bus for controlling the overall operation of the apparatus and the audio signal audio bus are separated, thereby minimizing noise due to digital signals in the digital system, and modularizing each component. It increases the reliability and makes it easy to expand the function.

2, the MUX unit 2 includes an A / D converter 21, a memory 22, a video signal generator 23, a time data and a control signal generator 24, and a DEMUX unit. (7) includes a data recovery circuit 71, a data conversion and memory control circuit 72, a memory 73, and a D / A conversion section 74. As shown in FIG.

Hereinafter, in FIG. 1 and FIG. 2, each detailed structure is demonstrated more concretely.

3 is a detailed configuration diagram of the signal input unit 1 in FIGS. 1 and 2. The signal input unit 1 receives voice signals of up to 24 lines from the outside and passes through the signal force detector 13 and the automatic gain regulator 11 to make each of the lines a constant signal force, and converts the signals into the MUX unit ( Outputs the sampled audio signal according to the sampling signal received from 2).

In FIG. 3, four circuits can be input to one module card for easy expansion according to the input circuit.

The automatic gain adjuster 11 always outputs a signal of -30 dB or more at 0 dB in order to maintain a constant voice force of each line to be recorded. The anti-aliasing filter 12 prevents an aliasing effect that occurs during sampling through a low pass filter (LPF) of 3.4 KHz in the output signal of the automatic gain adjuster 11.

The 4: 1 analog multiplexer 14 multiplexes the audio signal of each line passing through the filter 12 into a predetermined time slot according to the output signal from the comparator 15 and outputs the audio signal to the audio bus.

The signal force detector 13 detects whether a voice signal above the base noise level of the input line is input and is connected to the lamp indicator 16 to be externally adjustable. The lamp indicator 16 performs a display operation according to the output of the signal force detector 13.

Channel selection signals and card selection signals from the audio bus are input to the analog multiplex 14 and comparator 15, respectively.

4 is a detailed configuration diagram of the MUX portion 2 in FIGS. 1 and 2. The MUX unit 2 of FIG. 4 has a function of converting the multiplexed audio signal into a video signal for recording on a VHS recording. That is, the MUX unit 2 has an A / D conversion function for converting multiplexed analog voice signals into digital data, a memory bank management function for storing the converted data in memory, or reading necessary data from the memory, and an additional time data function. It includes a synchronization generating function for generating a vertical synchronization signal and a horizontal synchronization signal in accordance with the NTSC standard signal.

The MUX unit 2 includes an A / D converter 21, an image signal generator 23 of the memory 22, a time data and a control signal generator 24 as shown in FIG. A detailed description thereof will be described with reference to FIG. 4.

The WR counter 26 has a clock oscillator, divides 64 clocks into 11.0592 MHz to supply a sampling clock, generates 12 bits (A ₀ -A ₁₁ ) for storing data, and is required for multiplexing a voice signal. Provide a channel selection signal.

The A / D converter 21 receives a 172.8 KHz (Equation 1) clock and outputs an input signal within 2 Vpp as an 8-bit digital value.

The WR control circuit 25 intercepts the output timing of the data buffer 27 from the A / D converter 21 and the address buffer 27 'from the WR counter 26 and the WR control signal of the memory 22. Will generate

As shown in FIG. 4, the video signal generator 23 of FIG. 2 includes a synchronization signal generator 231, an RD counter 232, an RD control circuit 233, and a parallel-to-serial converter. Etc.)

The synchronizing signal generating circuit 231 outputs the horizontal synchronizing signal Hsyhc and the vertical synchronizing signal Vsync for the NTSC video signal, and the RD counter 232 generates addresses necessary for audio data and time data according to the synchronizing signal.

The RD control circuit 233 supplies a clock to the shift register 234, which is a parallel-to-serial converter, for outputting 16 channels (160 bits) of data converted into an NRZ signal every one raster period, and supplies the RD signal required for memory reading. Output

The shift register 234 generates and outputs a start bit, an end bit (Equation 3), and a sync byte while shifting parallel data to convert it into serial data.

The output circuit 28 combines serial data and sync signals to the NTSC standard level and supplies them to the two decks.

It consists of an 8-byte SRAM of memory 22 for storing voice data for two fields (actual audio data amount is 2 x 2880 bytes), and bank switching is performed using the most significant address bit A12. The RD address A12 and the WR address A12 are inverted and output for each vertical synchronization signal. In this way, one memory is divided into two banks so that read (RD) and write (WR) operations are performed using the cycle steal method.

The pulse generator 235 compares the RD signal with the WRE signal to allow the WR signal to be safely generated between the RD signals.

The time data is stored in the time register 29 from the central control section 5, and stored in a recognized address of the memory by the WR control circuit 25, and all the control signals operate in synchronization with the end of the vertical synchronization signal. do.

The NTSC signal from the MUX unit 2 as described above is recorded and stored in the recording deck 3.

5 is a detailed configuration diagram of the DEMUX unit 7 in FIGS. 1 and 2. In FIG. 5, the DEMUX unit 7 has a function of restoring a signal reproduced by the playback deck 6 to voice data, extracting a voice signal of a desired channel, and outputting it as a voice signal. That is, the DEMUX unit 7 attenuates the harmonic components of the square wave spectrum while passing through multiple stages of integrating circuits and video signal band filters for modulation for recording the serial data signal composed of NRZ inside the VHS recorder. Various noises are mixed by the state of the header, so it must be possible to remove the noise and reproduce the original original NRZ square wave. In addition, the data must be classified into the voice of each channel from the reproduced square wave and stored in the memory, and has the function of converting the data of the desired specific channel into the original audio signal.

The DEMUX unit 7 includes a data recovery circuit 71, a data conversion and memory control circuit 72, a memory 73, and a D / A conversion unit 74, as shown in FIG. A detailed description will be made using FIG. 5.

The data recovery circuit 71 is a circuit for recovering the NRZ square wave from the reproduced signal, and includes an automatic gain regulator 711, an envelope detection circuit 712, a comparator 713, a digital low frequency filtration circuit 714, and synchronous separation. Circuit 715.

The automatic gain adjuster 711 maintains a constant magnitude of the signal received from the playback deck 6, the envelope detection circuit 712 removes the level change of the waveform generated according to the frequency characteristics, the voltage comparator 713 is an image It is composed of high speed AMP for signal and outputs square wave without synchronous signal. The digital low frequency filtration circuit 714 generates the square wave an accurate NRZ signal having a constant bit period.

The configuration of the data conversion and memory control circuit 72 is as follows. The WR counter 721 is composed of a synchronous binary counter, and outputs a channel number and a memory address of data currently input by the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync extracted by the synchronization separation circuit 715.

The sp register 727 continuously outputs the reproduced serial data as parallel data, and the sync byte is detected by this signal.

The sync byte detector 728 is composed of a 10-bit comparator, which detects data in the form of sync bytes after the horizontal sync signal, and the WR control circuit 724 of the channel counter of each data is synchronized by this detection signal.

The channel number reproduced by audio is stored in the buffer 723, which is a register from the central controller 5 to the selection channel comparison circuit 722, and the voice data value is stored in the latch buffer 726 in comparison with the current channel number. do.

The WR control circuit 724 interrupts the output of the address buffer and the storage buffer to store voice data and time data of a desired channel at a specific address of the memory 72, and the pulse generator 725 is connected to the MUX unit 2 in the As shown in the figure, a write (WR) signal is output between memory read (RD) cycles.

6 is a detailed block diagram of the D / A conversion unit 74 in FIG.

RD counter 741 is composed of 64 division and 24 division counters for D / A conversion of 7.2 KHz sampled signal to 7.2 KHz for one voice line, and 120 voice data in one memory bank Output the address for reading.

The RD control circuit 742 receives 8-bit command data and supplies 7-bit voice data and the conversion clock except the least significant bit to the D / A converter 743 that outputs up to 2 Vpp audio and outputs the output of the address buffer 743. To control. The audio signal output from the D / A converter 743 is amplified with a gain of 2 and passed through a 3.4 KHz low pass filter 744 to obtain a desired audio audio signal.

Six bytes of time data stored in a specific area are read by the central control section 5 during every vertical synchronization, and the entire memory control is performed by the end of the vertical synchronization signal as in the MUX section 2. FIG.

7 is a detailed configuration diagram of the I / O control unit 4 in FIG.

It is necessary to be able to inspect the state of the two recording and playback decks and control the operation, and to receive the operation switch input of the previous part and notify the central control unit 5, and a connection connector for displaying various information on the liquid crystal display. The I / O control unit 4 has a function of allowing the central control unit 5 to control peripheral devices.

As shown in FIG. 7, the I / O unit 4 includes a deck control unit 41 for controlling two decks A and B, a front control unit 42 for controlling a front switch and a lamp LEP, It consists of an LCD connection portion 43 for displaying a liquid crystal display (LCD).

The deck controller 4 can command all functions through the deck remote control, and consists of a PIO chip having 24 I / O pins and a remote one-chip processor for reading the status of the deck and transmitting it to the central controller 5. do.

The front control part 42 scans 26 operation switches, receives an input, and is designed so that a PIO chip may be in charge of control of various lamps.

The LCD connection unit 43 supplies a data bus and a control signal so that the central control unit 5 displays various types of information on the LCD.

8 is a detailed configuration diagram of the central control unit 5 in FIGS. 1 and 2.

The central control unit 5, which controls the operation of the entire apparatus, includes a CPU 51, which is a high-speed 16-bit microprocessor, a ROM 52 in which a control program is stored, an SRAM 53 having a 64K byte capacity, and a Real Time Clook. 54), an I / O chip 56 having a WDT (Watch Dog Timer) 55, two serial ports 57, 58, and a printer 59.

The CPU 51 performs 16-bit operation at an operating speed of 8 MHz to externally access the 8-bit data bus and has a memory area of 1 M-bit.

The RTC 54 stores the current time at all times, and divides the frequency of 32.768 KHz to store the current time by itself.

The WDT 55 resets and initializes the CPU 51 when the program does not operate for 1.6 seconds or more due to a malfunction of the equipment, and backs up the RTC 54 and the SRAM 53 when the power is turned off by the backup battery for 3.6V. Data is preserved, and a stable reset signal is output when the power level is 4.65V or more when the power is turned on, and an NMI signal is output when the power is turned off to ensure stable operation of the CPU 51.

In addition, in FIG. 2, the audio output unit 8 amplifies the audio audio signal output from the DEMUX unit 7 and an alarm informing of the equipment abnormality to drive the speaker 9. This audio output section 8 is composed of an audio 2-watt amplifier, an RC oscillation section for outputting an alarm, a DTMF, a decoder, and the like.

As described above, according to the present invention, the voice signal is reproduced in the normal playback mode from the matching time by searching and comparing the time input from the user with the time data recorded on the tape at high speed.

Even in high speed playback, the vertical sync signal and horizontal sync signal are detected and the data are restored and stored in the memory (memory) .The time data are always stored together with the voice data, so it is possible to accurately identify the time when the voice was recorded. You can search and play the recording of the specific time you want.

That is, according to the present invention, an image having a wide bandwidth as a recording characteristic and popularized and easily available for purchase, using an industrial standard VHS-type video recording tape and a recorder, which requires multiplexed audio signals and time data. It can be converted into signal form, recorded on tape, and the recorded signal can be reproduced as original audio signal and time data through data recovery and conversion procedure.

As mentioned above, although the invention made by this inventor was demonstrated according to the said Example, this invention is not limited only to the structure of the said Example, Of course, it can change variously in the range which does not deviate from the summary.

Claims (4)

In the multi-channel voice recording and reproducing apparatus capable of multi-channel voice recording and retrieving recorded signals at high speed, an analog input from the signal input unit 1 and the signal input unit 11 for inputting an external voice signal A modulation means (2) for converting the signal into digital data, generating vertical and horizontal synchronization signals in accordance with the video standard signal, and converting the multiplexed audio signal into a video signal form; and recording and recording the signal from the modulation means (2). Demodulation means for reconstructing the reproduction signal in the form of video signal reproduced from the deck portion (3, 6) and the deck portion (6) for reproduction, into digital audio and time data, and extracting the audio data of a desired channel into an analog audio signal. (7) to control the modulating means (2) and the demodulation means (7), to inspect the state of the central control section (5) and the deck sections (3, 6) storing a control program and to control the operation thereof. mouth Power control unit 4, and multi-channel sound recording and reproducing apparatus comprising a sound output unit (8) for amplifying and outputting an error of the voice signal and the apparatus itself from said demodulating means (7). The method according to claim 1, wherein the modulating means (2) outputs the audio and time data in the form of a standard video signal by an A / D converter (21) for multiplexing a multi-channel analog audio signal into digital audio data. Multi-channel audio recording and reproduction comprising a video signal generator 23 and means 24 for outputting time data and control signals according to the control signals from the central control unit 5 to the video signal generator 23. Device. 2. The demodulation means (7) according to claim 1, wherein the demodulation means (7) is a data recovery circuit (71) for restoring an output signal from the reproduction deck (6) to an NRZ square wave, and the NRZ square wave as voice and time data. And means (72) for restoring and controlling the memory and the D / A converter (74) according to the control signal from the central controller (5). In particular, according to claim 3, the data recovery circuit 71 includes an envelope detection circuit 712 and a envelope detection circuit for removing the level conversion rate so that the output signal from the reproduction deck 6 is kept constant. A multi-channel voice recording and reproducing apparatus including a comparator 713 for outputting a square wave from which the synchronization signal is removed from the output signal of 712, and a digital low frequency filtering circuit 714 for outputting the output signal of the comparator 713 at a constant bit period. .