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 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 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.