Modernization of formant method of estimation of voice information protection from leakage through technical channels

This study is summary of research results of existing voice information security estimation approach analysis and modification, especially by change of immediate appreciation test conditions, along with considering speech forcing effect, adjustment of frequency range width and the method of its division, analysis of amplitude speech constitution and qualification of test signal level. Another point raised in the study is necessity of measurement certification of W (word intelligibility coefficient) estimating method. The updated approach is also suggested.