The phonological and phonetic encoding of information status in American English nuclear accents

Information structure is said to play an important role in determining phrasal prominence and the assignment of nuclear pitch accents in English. Early accounts claim that discourse-new or focused words receive a prominence-lending high/rising pitch accent, while given words are unaccented, with reduced prominence. Empirical findings are varied, but paint a more complex picture of the prosodic encoding of information structure. The present study investigated the phonological and phonetic encoding of information status and contrastive focus in nuclear position in American English, from speech read under neutral and lively affect. Given information was associated with decreased phonological and phonetic prominence, contrastive information with enhanced prominence, while new information corresponded to increased phonological, but not phonetic prominence, as assessed in pitch accent type, duration, intensity, and voice quality. The findings indicate a probabilistic relationship between information structure and nuclear pitch accent type, and gradient expression of information structure in acoustic prominence.