Individual differences in the signaling of prosodic structure by changes in voice quality

Abstract

Earlier work has shown that speakers of American English often (although not always) produce irregular pitch periods (or other changes in voice quality) at prosodically significant locations, such as the onset of a new intonational phrase or a pitch-accented syllable, when those constituents begin with a [ + voiced] phonemic segment (Pierrehumbert & Talkin 1992). This tendency varied substantially across 5 speakers of FM-Radio-News-style speech (Dilley et al. 1996). Further work with speakers of a west-coast dialect (Garellek 2012) raised questions about the appearance of this cue at phrase onsets, when the phrase begins with a prosodically weak (lexically unstressed) syllable; this suggests that it occurs only for phrasally-strong (pitch accented) syllables, whether they occur in phrase-initial position or not. In contrast, extensive analysis of voice quality changes in a corpus of imitated utterances produced by speakers of a mid-western dialect (Cole & Shattuck-Hufnagel 2011) clearly shows a tendency for voice-quality changes at the onsets of prosodically weak syllables when they occur at the onsets of intonational phrases. This raises the possibility that individual speakers or dialects may differ in the likelihood of using changes in voice-quality to mark different types of prosodic events, such as phrase onsets vs pitch accents.