SU1282192A2 - Device for suppressing pulse noise of sound track - Google Patents

Abstract

This invention relates to instrumentation engineering and makes it possible to increase the effectiveness of noise reduction. Frequency correction and frequency limitation of the signal received from the synthesizer unit 10 are performed using the signal spectrum controller 13. From the output of the attenuator 14, the signal enters the limiting amplifier 15, where the signal is limited. Using the envelope generator 16, an envelope of the signal from the output of the amplifier-limiter 15 is formed, which controls the transfer coefficient of the multiplier 17. A signal from the output of the signal spectrum regulator 13 is supplied to the signal input of the multiplier

Description

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la The transmission coefficient of the multiplier 17 increases with increasing signal level at the signal input up to a certain threshold, which is set using attenuator 14. When this threshold is exceeded, the transfer coefficient of multiplier 17 / becomes constant, k. limiting amplifier 15 goes into limiting mode. From the output of the multiplier 17, the signal through the attenuator 8 is fed to one of the inputs of the adder 11. In the process of noise reduction, an attenuator 14 is used which attenuates the residual noise in the pauses in the signal at the output of the signal synthesis synthesis unit 10. The attenuation of noise occurs in the frequency regions above the cut-off frequency of the low-pass filters 2. The invention is additional to the main ed. No. 980134. 1 Il.

one

The invention relates to instrument making, namely, devices for suppressing phonogram noise, and is an improvement of the known device according to the author. No. 980134.

The purpose of the invention is to increase the effect of noise reduction.

The drawing shows a functional diagram of a device for suppressing a pulse sound of a phonogram.

The device contains a two-channel pickup 1, the outputs connected through appropriate filters 2 low frequencies to different inputs of the total difference unit 3, the differential output 4 of which through serially connected shaper

5 pulses and generator control

6 impulses are connected to one of the inputs of the impulse noise suppression unit 7, to the second input of which, through the delay element, the summing output 9 of the total difference unit 3 is connected, the output of the impulse noise suppression unit 7 is connected to the inputs of the signal synthesis units 10, the outputs of which are loaded on the corresponding inputs of the adder 11, one of the inputs of the adder 11 is directly connected to the output of the impulse noise suppression unit 7, each signal synthesis synthesis unit 10 contains a serially connected transponator 12 spectrum a, regulator 13 of the signal spectrum, additional attenuator 14, amplifier-limiter 15, shaper 16 envelope multiplier 17. The second input of the multiplier 17 is also connected to the output of the regulator 13 of the signal spectrum, and the output of the multiplier 17 is connected to the attenuator 18, the output of which is The output of the signal synthesis block 10 is connected to one of the inputs of the adder 11. The envelope shaper 16 comprises a detector and a low-pass filter.

The device works as follows.

With the help of a two-channel pickup 1, signals are read from a record (not shown), then the frequency range of the read

The signals are bounded above by both channels using low-pass filters 2 with a cut-off frequency of, for example, 3 kHz. At the same time the energy of impulse noise of short duration,

the spectrum is very wide, greatly reduced. In the total difference block 3, the signals of both channels are added and subtracted. With

in addition the components are reduced

impulse noise, when subtracting, the components of the useful signal are subtracted, and the components of impulse noise add up, which increases the interference / useful signal ratio

during subsequent processing, the detection accuracy of pulse interferences of medium and long duration increases.

From a signal with a twisted noise / signal ratio, a sequence is formed. the pulses received at the input of the controlled generator of 6 pulses from the output of the KOTopoj-o pulse sequence is fed to

the first input of the impulse noise suppression unit 7, to the second input of which a signal with an increased signal-to-noise ratio is fed through the delay element 8. At the output of the impulse noise suppression unit 7, impulse noise of medium and long duration is suppressed. From the output of block 7, suppression of pulsed interference signal, in which the level of pulsed interference is reduced, is fed to the inputs of blocks 10 of the synthesis of the signal spectrum. In each of them, the signal spectrum is transformed with the help of a transponder.

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The nuch 15 goes into the restriction mode. From the output of the multiplier 17, the signal through the attenuator 18 is applied to one of the inputs of the adder 11,

In the process of noise suppression (operation), the operator, using the additional attenuator 14, attenuates the residual (band-pass) noise in the pauses in the signal at the output of the signal spectrum synthesis unit 10. Moreover, the attenuation of noise occurs in the frequency regions above the cut-off frequency of the low-pass filters 2. Some decrease

12 of the spectrum, and the coefficient of trans-5 coefficients (multiplier transmission 17

Sponsoring in each of the blocks 10 of the synthesis of the signal spectrum is different. The frequency correction and the frequency limitation of the received signal are performed using the signal spectrum adjuster 13. From the output of the additional attenuator 14, the signal is then fed to a limit amplifier .15, where the signal is limited. Using the shaper 16 of the envelope, the envelope of the signal coming from the output of the amplifier-limiter 15 is formed. This envelope of the signal controls the transmission coefficient of the multiplier 17, the signal input of which is fed from the output of the regulator 13 of the signal spectrum. The multiplier 17's transmission coefficient increases with increasing signal level at the signal input up to a certain threshold, which is set with the help of an additional attenuator 14. When this threshold is exceeded, the multiplier 17 transmission coefficient becomes constant, because the amplifier is

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in quiet areas of the sound program, when a low level signal spectrum is received at the output of the regulator 13 does not affect the sound quality of the processed phonogram, since in the silent sections the spectrum of most musical instruments is narrowed.

Claims (1)

Invention Formula A device for suppressing pulsed phonogram noise according to the author No. 980134, characterized in that, in order to increase the noise reduction efficiency, an additional attenuator, an amplifier-border, a reader, a signal envelope former and a multiplier connected between the output of the spectrum regulator and the attenuator input, moreover, the spectrum controller is connected to one of the multiplier inputs by an output. 40 The nuch 15 goes into the restriction mode. From the output of the multiplier 17, the signal through the attenuator 18 is applied to one of the inputs of the adder 11, In the process of noise suppression (operation), the operator, using the additional attenuator 14, attenuates the residual (band-pass) noise in the pauses in the signal at the output of the signal spectrum synthesis unit 10. Moreover, the attenuation of noise occurs in the frequency regions above the cut-off frequency of the low-pass filters 2. Some decrease in quiet areas of the sound program, when a low level signal spectrum is received at the output of the regulator 13 does not affect the sound quality of the processed phonogram, since in the silent sections the spectrum of most musical instruments is narrowed. Invention Formula A device for suppressing pulsed phonogram noise according to the author No. 980134, characterized in that, in order to increase the noise reduction efficiency, an additional attenuator, amplifier-edge, a signal envelope generator, and a multiplier connected between the output of the spectrum regulator and the attenuator input are inserted into each block of the signal spectrum synthesis, the spectrum controller is connected to one of the multiplier inputs by the output;