Speech analysis and reconstruction using short-time, elementary waveforms

Abstract

We consider the speech signal to be composed of elementary waveforms, wf, (windowed sinusoids), each one defined by a small number of parameters. The typical duration of a wf is of the order of magnitude of a pitch period in the voiced segments, and a few milliseconds in the noise segments. No preliminary evaluation of voicing or pitch is required ; this largely differentiates the approach from the classical pitch-synchronous analysis. The analysis process uses a filterbank, designed to introduce as few time distortions as possible. The signal at the output of each filter is segmented according to successive amplitude minima, and each segment is modeled by a wf. This decomposition can be validated by reconstructing the wfs from their parameters, and summing them in order to recover a signal perceptually equivalent to the original.