Spectral slope as a cue for the perception of breathy and non-breathy stops in Shanghainese

Abstract

In Shanghainese, breathy excitation following release distinguishes category 2 (so-called “voiced unaspirated”) stops from category 1 (“voiceless unaspirated”) stops. The most obvious acoustic correlate of bresthiness is relative spectral slope: During the first 50–100 ms after release, H1-H2 is greater for category 2 than for category 1 in both word-initial and word-medial (morpheme-initial) stops (Ren, unpublished). To investigate the perception of breathiness, a series of synthetic disyllables was prepared in which the spectral slope during the 100 ms following the release of the word-medial stop was increased step by step increasing the value of the “open quotient” in the computation of the glottal waveform—a technique previously used for the synthesis of breathy vowels [C. Bickley, Work. Papers MIT Speech Commun. Lab. 1, 71–81 (1982)]. Other potential cues (closure duration, pulsing during closure, tone contour) were neutralized. Ten Shanghainese speakers labeled the stimuli with greater spectral slope as category 2 and those with smaller spectral slope as category 1. [Work supported by NICHD Grant 01994.]