On the acoustic cues of unreleased stops

Abstract

Unreleased stops, lacking a burst, have been claimed to have low perceptibility and are more likely to neutralize place contrasts. While this proposition has been supported by examining no-burst VC fragments spliced from released stops, little is known about the acoustic discriminability among true unreleased stops. This study fills this gap by analyzing the acoustic correlates of VC (where C = unreleased stops p̚, t̚, k̚, ʔ) in Cantonese and Taiwanese Southern Min. Specifically, duration and formant transitions were estimated across three distinct contexts: VC-V vs. VC#V vs. VC#C. The preliminary results are (a) the formant transitions are effective cues to place contrasts of the unreleased stops: the labial has low F2 offset frequency, the coronal has high F2, and the dorsal has low F3, (b) the magnitude of transition cues varies with different contexts: the cues are more significant when followed by a vowel-initial, lexical morpheme (VC#V) than by a consonant-initial or functional morpheme (VC#C, VC-V), and (c) vowel raising is resisted in the dorsal-final environment. This finding may have implications for the phonotactic constraint *[ + high][high] in the two languages.