RU33282U1 - Device for protecting voice information via vibro-acoustic channel - Google Patents

Abstract

A device for protecting speech information through a vibro-acoustic channel, containing a power source, a master oscillator, a pulse shaper, characterized in that it additionally includes an M-sequence pulse shaper, an adjustable matching device, an indication block of interference and control of the communication line, a device for converting electrical vibrations into vibration wherein the output of the master oscillator through sequentially connected pulse shaper M-sequence, regulating matching devices , the block of indication of interference and control of the communication line is connected to the device for converting electrical vibrations into vibration, and the output of the power source is connected to the input of the master oscillator of the pulse shaper M-sequence, adjustable matching device, block of indication of interference and control of connecting lines, device for converting electrical vibrations into vibration .

Description

A device for protecting voice information over a vibro-acoustic channel.

The device relates to the field of radio engineering, in particular to devices for protecting information from enclosed spaces from unauthorized listening and recording.

Known devices designed to protect speech information in rooms in which indoors, on its internal reflective surfaces, or directly on window panes, acoustic vibrations with an amplitude known to exceed the amplitude of vibrations of a human voice (see, for example, UI 24610RU 7 NIGHT 3 / 00 A device for masking vibro-acoustic noise suppression of a room (options) / Rohmashok V.M., Fokin E.M., CJSC ANNA, - 2002 112903/20; claimed 20.05.2002, UI 27442 RU 7NOCH 3/00 Device for vibro-acoustic noise of a room / Rohmanyuk V.M., Fo Kin E.M., CJSC ANNA, -2002 109695/20; APPLICATION. 04.16.2002)

The disadvantages of such devices consist mainly in the fact that the so-called “acoustic white noise is quite easily filtered using a selection of frequencies that are obviously not appropriate for the human voice. And from the rest of the spectrum of acoustic noise by expanding it in amplitude and frequency, the modulating vibrations inherent in the human voice are quite easily distinguished.

The proposed device closest in technical essence is the invention CI 210697 RU 6 NOCM 1/68 A method for protecting speech information from listening and recording / Ratnikov A.Yu., Yuryev D.N., Kapralov G.N. - 98103645.09; declared 02.24.1998.

The device that implements the method according to patent CJ 2130697 RU 6NOCHM 1/68, selected as a prototype includes determining the amplitude-frequency characteristics of the voices of persons participating in the exchange of information and generating acoustic noise with a certain amplitude-frequency characteristics and contains a noise analyzer, noise shaper, amplifier, emitter, power supply, etc.

The prototype has the following disadvantages, when protecting information with noise interference, there are effects that interfere with negotiating in a protected room, and radiation of noise interference into the environment affects the operation of nearby electronic equipment. Direct noise suppression of speech signals in

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NIGHT 3/00 NIGHT 1/68

intelligence conditions are not very effective, because Existing interference suppression measures result in the need to ensure effective signal-to-noise ratios in the octave bands of up to 20 dB. This leads to the fact that negotiations in a protected room becomes difficult to carry out.

Thus, the device solves the problem of increasing the effectiveness of technical means of information protection and reducing the effects of radiation on people conducting real negotiations in a protected room, and radiation into the environment.

To solve this problem, in a known device containing a power source, a master oscillator, a pulse shaper, an adjustable matching device, an indication block of interference and control of connecting lines, a device for converting electrical vibrations into vibration are additionally introduced. The pulse shaper is configured to generate an M-sequence of pulses, and the device for converting electrical vibrations into vibration is made with the possibility of hard contact of the vibration sensor with the structural elements of the room. The output of the master oscillator through series-connected pulse shaper of the M-sequence, an adjustable matching device, a block of indication of interference and control of the connecting lines are connected to a device for converting electrical vibrations into vibration. This approach is based on the multiplicative effect of interference on the protected element of the building structure with an M-sequence of pulses, which is transformed due to the inertia of the structure into normal noise with a simultaneous decrease in the amplitude of the protected signal.

This leads to a decrease in the amplitude of the protected signal at the building structure element, and, accordingly, at the input of the acoustic reconnaissance receiver. Thus, the claimed technical solution, the device for protecting voice information through a vibro-acoustic channel meets the criterion of a utility model.

It is this new property of the totality of the elements of the utility model in the proposed relationship that leads to the emergence of a new quality - to increase the effectiveness of technical means of information protection and reduce their impact on subjects negotiating in a protected room.

information on the elements of building structures.

In FIG. 1 is indicated by:

1- power supply;

2- master oscillator;

3- pulse shaper M-sequence;

4- adjustable matching device;

5- block indication of interference and control of connecting lines;

6- device for converting electrical vibrations into vibration.

The device for protecting voice information through a vibro-acoustic channel consists of a power source 1, a master oscillator 2, an M-pulse trainer 3, an adjustable matching device 4, an indication block of interference and control of connecting lines 5, and a device for converting electrical vibrations into vibration 6.

A device for protecting voice information in a vibro-acoustic channel operates as follows. They turn on the power source 1, the master oscillator - 2 generates pulses that are fed to the pulse shaper M-sequences - 3. The generated M-sequence of pulses through an adjustable matching device - 4, as well as an indication block of interference and control of connecting lines - 5, is fed to the electrical conversion device vibrations in vibration - 6.

A device for converting electrical vibrations into vibration 6 is rigidly fixed to an element of a building structure (glass). Coordination of the output resistance of the pulse shaper M-sequence and the input resistance of the device for converting electrical vibrations into vibration 6, provides an adjustable matching device - 4.

A unit for indicating interference and connecting line control - 5 is connected to the above device, which provides:

-indication of the inclusion of the device;

The device provides protection from listening and recording voice information on vibroacoustic kgshal.

The results of experimental studies of the ability to protect acoustic speech information on the elements of building structures are presented in FIG. 2. where:

in FIG. 2a shows a spectrum of a vibroacoustic signal obtained as a result of the action of a noisy vibroacoustic signal on a tonal acoustic signal;

in FIG. 26 shows a spectrum of a vibroacoustic signal obtained as a result of the influence of a vibroacoustic signal of type M-sequence on a tonal acoustic signal.

The results presented in FIG. 2 show that the total power of the acoustic speech signal received by means of acoustic voice reconnaissance decreases approximately two times when a pulse signal is applied to the surface to be protected. As a basic signal, the M-sequence is used, which allows you to generate a noise signal on the protected structural element of the protected space, which is formed due to the inertia of the elements of building structures.

The experiment was carried out in two stages.

The object of experimental research was a window glass measuring mm, rigidly fixed to the frame with four sides.

For experimental studies, 2 laboratory units were assembled.

The first, designed to assess the impact of a vibroacoustic noise signal on an acoustic speech, consisted of a normal noise generator, a 2209 type sound level meter company Bruhl and Kier, designed to pick up a signal from window glass and its amplification, a spectrum analyzer of type SK-4 / 72-2, designed to indicate the effects of interference on the signal and the Boomerang product, designed to generate a model of a reference (protected) acoustic speech signal.

The second one, designed to assess the effect of the M-sequence vibro-acoustic signal on the acoustic speech, consisted of a Sequence generator, a 2209 type level meter from Bruehl & Kier, a SK-4 / 72-2 type spectrum analyzer and a Boomerang.

Noise from the generator to the glass was supplied through a device for converting electrical vibrations into vibration ZP-3. The amplitude of the signal to be protected by sound pressure was 80 dB. The effective voltage of the noise generator on ZP3 was 5 V.

At the first stage, noise and M-sequence were alternately applied to the glass. The resulting signal was recorded by a spectrum analyzer. In this case, the resonance frequency of the ZP-3 + glass system was determined. The natural resonant frequency of the ZP-3 + glass system was approximately 2.2 kHz. The frequency of the signal to be protected is selected. The choice of frequency was made based on the condition that the ZP-3 + glass system did not fall into the main peak of its own resonance and fell into the effective range of speech frequencies of 300-3400 Hz. Since the upper part of the effective range of speech is overlapped by this peak, a tone signal at a frequency of 700 Hz was chosen as the model of the protected signal. In addition, by comparing the spectral density of interference of both generators and the subsequent tuning of the generator of the M sequence, the same spectral density of interference on the glass is ensured.

At the second stage, a Boomerang acoustic generator was installed at a distance of 2 m from the test object, and a harmonic acoustic signal with an amplitude of 80 dB at a frequency of 700 Hz was supplied from it. A glass signal and an M-sequence were alternately applied to the glass through ZP-3. The experimental results averaged over 1000 implementations are presented in FIG. 2.

Comparison of the spectra of FIG. 2a and FIG. 26 allows us to argue that the proposed device for the protection of voice information through a vibro-acoustic channel allows to reduce the amplitude of the interference signal on structural elements in integrated rooms by reducing the level of the protected signal, and, accordingly, to improve the conditions for negotiating.

Above the specified device is implemented on the element base of domestic production.

Claims (1)

A device for protecting speech information through a vibro-acoustic channel, containing a power source, a master oscillator, a pulse shaper, characterized in that it additionally includes an M-sequence pulse shaper, an adjustable matching device, an indication block of interference and control of the communication line, a device for converting electrical vibrations into vibration wherein the output of the master oscillator through sequentially connected pulse shaper M-sequence, regulating matching devices , the block of indication of interference and control of the communication line is connected to the device for converting electrical vibrations into vibration, and the output of the power source is connected to the input of the master oscillator of the pulse shaper M-sequence, adjustable matching device, block of indication of interference and control of connecting lines, device for converting electrical vibrations into vibration .