Third European Conference on Speech Communication and Technology

Berlin, Germany
September 22-25, 1993


Waveform Similarity Based Overlap-Add (WSOLA) for Time-Scale Modification of Speech: Structures and Evaluation

Marc Roelands, Werner Verhelst

Vrije Universiteit Brussel, Faculty of Applied Science, dept. ETRO, Brussels, Belgium

A synchronization criterion for overlap-add time-scale modification is derived through a least squares estimation of the modified short-time Fourier transform. Based on this finding, a structural time-domain framework for time-scale modification is described. One efficient variant, which was called the Waveform Similarity based Overlap-Add (WSOLA) method, produces high quality output when applied to speech, but can even be applied successfully to a broader class of signals, including multiple voices together and musical instruments. Fine-tuning the synchronization criterion, without affecting the high quality that is obtained, can make the computational cost very low, revealing the versatile possibilities for on-line operation.

Full Paper

Bibliographic reference.  Roelands, Marc / Verhelst, Werner (1993): "Waveform similarity based overlap-add (WSOLA) for time-scale modification of speech: structures and evaluation", In EUROSPEECH'93, 337-340.