An auditory-based measure for improved phone segment concatenation

This paper describes a new auditory-based distance measure intended for use in a concatenated synthesis technique wherein the time- and frequency-domain characteristics are used to perform natural-sounding speaker synthesis. Whereas most concatenation systems use large databases (often +100,000 units), we begin from a small, limited database (approx. 400 units) and use a new spectral distortion measure to aid in the selection of phones for optimal concatenation. At the transition between speech segments, the new auditory-based distance metric assesses perceived discontinuities in the frequency domain. The distortion measure, which employs the Carney (see J. Acoust. Soc. Am., vol.93, p.401-17, 1993) auditory model, is used to select phones which minimize the perceived distortion between concatenated segments. Moreover, time- and frequency-domain methods can shape the prosodic and spectral characteristics of each speech segment. The final results demonstrate improved performance over standard concatenation methods applied to small databases.