A.S. Kolokolov, I.A. Lubinski, A.Yu. Mestcherakov, V.P. Yachno

A computer program for study of speech signal informative features is developed. At the core of the program is used the procedure of analysis-synthesis, which is complemented by a graphical editor of the signal dynamic spectrogram. Because of the editing there can be deleted the selected cursor frequency components of the speech signal. The dynamic spectrogram editing is implemented as a sequential procedure. At each step this procedure there can be suppressed by a variety of rectangular fragments of spectrum allocated to the frequency - time area. So removing by the spectrum editing certain frequency components of speech and listening signal after editing, one can draw at conclusions about the importance of certain frequency components in the perception of sound and bring to light its informative cues. By means of the developed program a study of informative cues of a speech signal is conducted. The results of the study showed that the phonetic information about the vowel is redundant and transmitted independently on several relatively narrow non-overlapping frequency bands. On this basis, concluded that the traditional description of vowels in terms of the first 2-3 formants needs revision. It is shown that phonetic quality of the fricative consonant can sharply change when its low-frequency components are removed.