FIELD: physics.
SUBSTANCE: invention claims systems and methods of speech signal classification and coding. Signal classification passes over three stages, with recognition of a definite signal class at each stage. First, active speech detector recognises active and inactive speech frames. If an inactive speech frame is found, the classification is finished, and the frame is encoded by comfortable noise generation. If an active speech frame is found, it undergoes second classification recognising non-vocalised frames. If the frame is recognised as non-vocalised speech signal, the classification is finished, and the frame is encoded by a method optimised for non-vocalised signals. In the opposite case, the speech frame is directed to 'stable vocalised' signal classification module. If the frame is classified as a stable vocalised frame, it is encoded by a method optimised for stable vocalised signals. In the opposite case, if the frame contains instable speech segment, e.g. vocalised initial or rapidly evolving signal, then a speech coder is applied.
EFFECT: improved speech quality at a given average data transfer speed.
84 cl, 12 dwg, 5 tbl
