Subband stationarity analysis of speech signals

A subband analysis of the stationarity characteristics of speech signals is performed. The analysis is based on the evaluation of seven distance measure techniques between consecutive speech segments. The overall ensemble comprised a total of 600 speech sentences each of duration varying from 2 s to 3 s, generated by two male and one female speakers. Segment lengths of 10 ms to 30 ms were considered. The experiments have shown that: most distance measure techniques yielded equivalent results; segments of 10 ms presented greater level of stationary between 0 and 1 kHz; for other lengths, all bands presented similar stationarity degrees. Results can be applied for a proper subband speech processing (e.g., coding) that depends on the stationary assumption of the signals involved.