Even common acquaintance with a modern status of researches in the field of audioinformation security methods effectiveness analysis reveals enough dangerous situation consisting in common approach to given class problems solution lack for today. It naturally entails variety of different not interconnected scrambling quality rating methods which practical value leaves to wish the best. Indeterminacy of rating optimality criteria used, frequently forces contributor to make the empirical solutions reducing usually doubtful results. Though attempts of the criteria using, providing scrambling methods separation (computing resistant and unconditionally resistant) justify themselves in some cases, however as a whole, insert additional indeterminacy. All this promotes forming a situation in which judgment that the level and a degree of speech scrambling systems privacy are rather conventional concepts is dominant. Introduction of virtual scrambling noise concept allows solving this problem. Taking this concept into consideration scrambling process may be submitted as modification of voice call S(t) by virtual noise V(t) process. The projection of this performance to the real area is defined by the expression:
, 
(1)
Where: E (t) is scrambled signal; 
is projection of virtual noise. Expressions (1) define common mathematical model of scrambling methods effectiveness rating. Researches in the given approach realization field give quite reassuring results. The testimony to this was creation of a hardware-software complex of audioinformation security current quality control.
The complex is intended for audioinformation quality control in real-time mode. Virtual rating algorithms are applied for these purposes for the first time. It allows using traditional performances utilized for purposes of audioinformation quality rating estimation: intelligibility and average information content. On its basis the possibility to recommend users how to organize private talks is provided. Given results are obtained during researches spent by writers at support of Russian federation Education Ministry T02-03.1-816.
