Focus effects on acoustic cues to sibilant place of articulation

Abstract

Prosodically driven contrast enhancement has been reported for vowels and consonantal voicing, but limited evidence of such prosodic strengthening effects has been found for consonantal place of articulation (e.g., Cole et al. 2007, Silbert & de Jong 2008). Chang and Shih (2015) extended similar investigation to the Mandarin alveolar-retroflex contrast. They had participants disambiguate an alveolar or retroflex syllable with phonologically unrelated syllables (e.g., contrasting /sa/ with /bo/) and found no focus enhancement of the alveolar-retroflex contrast. The current study investigated whether employing a smaller contrastive focus domain (i.e., disambiguating contrastive sibilants, such as contrasting /sa/ with /ʂa/) would give rise to sibilant hyperarticulation. Map tasks with stimuli that were vowel context-balanced and lexical frequency-controlled were used for elicitation of focused and unfocused productions of Mandarin alveolars and retroflexes. Results showed that contrastive focus results in adjustments of non-contrastive properties (i.e., longer syllable and frication duration, as well as higher frication amplitude) without enhancing the feature-defining dimension (i.e., a greater acoustic distance between alveolar and retroflex sibilants). Along with evidence from English /s/ and /ʃ/ in Silbert & de Jong (2008), it is suggested that the place contrast of coronal sibilants is less subject to cue-enhancing hyperarticulation.