SPEECH PLAYBACK SPEED CHANGE USING WAVELET CODING, PREFERABLY SUB-BAND CODING

摘要

A method of speeding up playback of a digitised audio signal without raisingthe pitch and without introducing discontinuities in the speech signal, comprises sub-bandcoding (SBC) consecutive blocks of the audio signal with standard SBC or waveletcompression to derive frames of data. Next periodic adjacent pairs of the frames aredropped to leave a stream of remaining frames. A sped up approximation of the digitisedaudio signal is then reconstructed by sub-band decoding consecutive remaining frames. Themethod can also be used to slow speech playback by replicating, rather than dropping,adjacent pairs of frames.