Development of a mathematical model of scrambler-type speech-like interference generator for system of prevent speech information from leaking via acoustic and vibration channels

Volodymyr Blintsov, Sergey Nuzhniy, Yurii Kasianov, Viktor Korytskyi


The protection of speech information is one of the main tasks of information protection and is a sign of a responsible attitude of an organization (company) both to its information resources and respect for partners. The object of research is the process of protecting speech information from leakage by acoustic and vibrational technical channels at the objects of information activity. An exceptional feature of such facilities is the circulation, processing and discussion of issues containing information of limited access, including state secrets. A peculiarity of Ukraine is the requirement to use exclusively technical means that have passed the relevant certification at such facilities.

The basis of the active noise jamming system is a noise generator. At the same time, one of the most problematic issues is that in Ukraine only noise interference generators of the “white” noise type and its clones are allowed to be used. The systems have a number of significant drawbacks – the low protection level of intercepted speech signals from noise filtering (interference), a significant noise level in the premises to be protected, and others.

A block diagram of an interference generator is proposed. And its mathematical model is also developed and researched in Matlab. In the course of the research, a comparative analysis of the signals input and synthesized by the generator was carried out, their temporal and spectral characteristics were investigated. The obtained results indicate the high efficiency of the proposed method of protecting speech information. This is due to the fact that the method of forming a speech-like interference has a number of features that provide a significant destructive effect on speech information, namely the use of a combined scrambler model with time and frequency transforms. The method takes into account the use of dynamic keys for coding systems, and the connection of third-party sources of speech signals, as well as ringing (mixing of the input and output signals) at the input of the scrambling unit. This decision excludes reengineering.

The results are confirmed by the research of an experimental sample. The destructive effect of typical noise interference («white» noise and its clones) and the noise interference created by the proposed method are compared by the criterion of residual speech intelligibility of the speaker’s speech. Studies have shown that, provided that no more than 10 % of the level of residual intelligibility is provided, the volume level of the output signal of the noise interference generator can be reduced by almost 6 dBA.


scrambler-type speech-like generator; protection of speech information; information protection


On Protection of Information in Automated Systems. Law of Ukraine No. 80/94-ВР. 05.07.1994. Available at:

On State Secret. Law of Ukraine No. 3855-XII. 21.01.1994. Available at:

On Protection of Personal Data. Law of Ukraine No. 2297-VI. 01.06.2010. Available at:

Normatyvnyi dokument systemy tekhnichnoho zakhystu informatsii ND TZI 2.4-010-2015. Available at:;jsessionid=D90D601C55F63184CFC22F8E76C42F44.app1?art_id=149166&cat_id=89991

Normatyvnyi dokument systemy tekhnichnoho zakhystu informatsii ND TZI 2.3-019-2015. Available at:;jsessionid=D90D601C55F63184CFC22F8E76C42F44.app1?art_id=149166&cat_id=89991

Normatyvnyi dokument systemy tekhnichnoho zakhystu informatsii ND TZI 2.2-008-2015. Available at:;jsessionid=D90D601C55F63184CFC22F8E76C42F44.app1?art_id=149166&cat_id=89991

Perelik zasobiv tekhnichnoho zakhystu informatsii, dozvolenykh dlia zabezpechennia tekhnichnoho zakhystu derzhavnykh informatsiinykh resursiv ta informatsii, vymoha shchodo zakhystu yakoi vstanovlena zakonom (stanom na 30 lypnia 2018). DSSZZI Ukrainy. Available at:

Vidomosti pro zasoby tekhnichnoho zakhystu informatsii, na yaki zakinchyvsia termin dii sertyfikativ vidpovidnosti ta ekspertnykh vysnovkiv (stanom na 1 sichnia 2017 roku). DSSZZI Ukrainy. Available at:

Grigorev, I. A., Kazanovskii, A. I. (2010). Metodicheskii podkhod k ocenke effektivnosti zaschity rechevoi informacii. Vestnik Voronezhskogo gosudarstvennogo tekhnicheskogo universiteta, 5, 133–136.

Nuzhnyi, S. M. (2018). Udoskonalena tekhnolohiia otsinky stupenia zakhystu movnoi informatsii. Suchasnyi zakhyst informatsii, 1 (33), 66–73. Available at:

Khorev, A. A. (2009). Ocenka vozmozhnostei sredstv akusticheskoi (rechevoi) razvedki. Specialnaia tekhnika, 4, 49–63.

Blintsov, V., Nuzhniy, S., Parkhuts, L., Kasianov, Y. (2018). The objectified procedure and a technology for assessing the state of complex noise speech information protection. Eastern-European Journal of Enterprise Technologies, 5 (9 (95)), 26–34. doi:

Rybalskii, O. V., Solovev, V. I., Zhuravel, V. V. (2017). Fraktalnii podkhod k vyiavleniiu sledov cifrovoi obrabotki v analogovykh fonogrammakh. Suchasna specіalna tekhnіka, 1, 4–9. Available at:

Solovev, V. I., Rybalskii, O. V., Zhelezniak, V. K. (2014). Multifraktalnaia struktura shepota i raspoznavanie rechevykh struktur. Vestnik Polockogo gosudarstvennogo universiteta. Seriia C, Fundamentalnye nauki, 12, 16–20. Available at:

Bortnikov, A. N., Gubin, S. V., Lobov, V. A., Siromashenko, A. V., CHernyshov, P. V. (2007). Rezultaty eksperimentalnykh issledovanii ocenki vozmozhnostei perekhvata rechevoi informacii pri realizacii metodov dvukhkanalnogo sema. Voprosy zaschity informacii, 1, 11–17

Lobov, V. A., Siromashenko, A. V., Chernyshov, P. V. (2007). Ocenka vozmozhnostei perekhvata rechevoi informacii pri realizacii metoda mnogokanalnogo sema. Voprosy zaschity informacii, 4, 27–35.

Licklider, J. C. R. (1948). The Influence of Interaural Phase Relations upon the Masking of Speech by White Noise. The Journal of the Acoustical Society of America, 20 (2), 150–159. doi:

Shannon, C. E. (1998). Communication In The Presence Of Noise. Proceedings of the IEEE, 86 (2), 447–457. doi:

Miller, G. A., Licklider, J. C. R. (1950). The Intelligibility of Interrupted Speech. The Journal of the Acoustical Society of America, 22 (2), 167–173. doi:

Bolt, R. H., Beranek, L. L., Newman, R. B. (1952). Handbook of acoustic noise control. Volume I. Physical Acoustics. doi:

Rosenblith, W. A., Stevens, K. N. (1953). Handbook of acoustic noise control. Volume II. Noise and man. doi:

Palomäki, K. J., Brown, G. J., Wang, D. (2001). A binaural model for missing data speech recognition in noisy and reverberant conditions. Consistent & Reliable Acoustic Cues for sound analysis. Aalborg.

Do, C.-T., Stylianou, Y. (2018). Weighting Time-Frequency Representation of Speech Using Auditory Saliency for Automatic Speech Recognition. Interspeech 2018. doi:

Prodeus, A. M., Vityk, A. V., Didenko, D. Y. (2017). Subjective evaluation of quality and intelligibility of speech distorted by synthesized noise. Microsystems, Electronics and Acoustics, 22 (6), 56–63. doi:

Smaragdis, P. (2009). Relative-pitch tracking of multiple arbitrary sounds. The Journal of the Acoustical Society of America, 125 (5), 3406. doi:

Wang, Q., Muckenhirn, H., Wilson, K., Sridhar, P., Wu, Z., Hershey, J. R. et. al. (2019). VoiceFilter: Targeted Voice Separation by Speaker-Conditioned Spectrogram Masking. Interspeech 2019. doi:

Renevey, P., Drygajlo, A. (2001). Entropy based voice activity detection in very noisy conditions. EUROSPEECH-2001,1887–1890. Available at:

Özaydın, S. (2019). Examination of Energy Based Voice Activity Detection Algorithms for Noisy Speech Signals. European Journal of Science and Technology, 157–163. doi:

Kasianov, Yu. I., Nuzhnyi, S. M. (2016) Otsiniuvannia efektyvnosti heneratora realnoi movopodibnoi zavady za kryteriiem rozbirlyvist movy. Visnyk Natsionalnoho universytetu "Lvivska politekhnika". Seriia: Avtomatyka, vymiriuvannia ta keruvannia, 852, 105–110. Available at:

Khorev, A. A., Makarov, Iu. K. (2001). Metody zaschity rechevoi informacii i ocenki ikh effektivnosti. Specialnaia tekhnika, 4, 22–33.

GOST Style Citations

Copyright (c) 2019 Volodymyr Blintsov, Sergey Nuzhniy, Yurii Kasianov, Viktor Korytskyi

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

ISSN (print) 2664-9969, ISSN (on-line) 2706-5448