Choice of Model of Test Signal at an Assessment of Security of Speech Information from Leakage through Technical Channels

Revaluation of the basic dependences which are used in the method of an assessment of security of speech information from leakage through technical channels is made. The statement and results of experiment for definition of formant distribution for cases of the usual and forced speech are described. Using these distributions it is possible to define contributions of frequency bands to total legibility of speech. Dependence of word legibility on formant legibility for a case of forced speech is received. The paper presents an experiment to determine amplitude structure of the speech by results of which conclusions of sufficient levels of a test signal are drawn for an assessment of security of speech information.