Modeling and synthesis of the lateral consonant /l/

Abstract

The lateral consonant in English is generally produced with a backed tongue body, a midline closure of the tongue blade at the alveolar ridge, and a path around one or both of the lateral edges of the tongue blade. In prevocalic lateral consonants, the release of the closure causes a discontinuity in the spectral characteristics of the sound. Past attempts to synthesize syllable-initial lateral consonants using formant changes alone to represent the discontinuity have not been entirely satisfactory. Data from prior research has shown rapid changes in not only the formant frequencies but also in the glottal source amplitude and spectrum and in the amplitudes of the formant peaks at the consonant release. Further measurements have been made on additional utterances, guided by models of lateral production. Based on these data, new synthesis attempts have incorporated changes in source amplitudes, formant bandwidths, and the location of a pole-zero pair. Including these additional parameters improves the naturalness of the synthesized lateral-vowel syllables in initial perception tests. Results of listening tests indicating the relative importance of the various factors to the naturalness of the synthesized syllables will be reported. [Work supported in part by a LeBel Fellowship and by NIH Grant No. DC00075.]