Perception of correlations between acoustic cues in category tuning and speaker adaptation

Abstract

In English and many other languages, fundamental frequency (f0) varies with voicing such that voiced consonants are produced with lower f0’s than their voiceless counterparts. This regularity robustly influences perception, such that sounds synthesized or spoken with a low f0 are more often perceived as voiced than are sounds with a higher f0. This series of studies exploited these observations to investigate category tuning as a function of incidental exposure to correlations among speech cues and adaptation to speaker idiosyncrasies or accent. Manipulation of f0 across sets of natural speech utterances produced stimulus sets varying in their inherent f0/voicing relationship. Listeners were exposed to these different f0/voicing patterns via spoken word and nonword items in a lexical decision task, and their resulting categorization of ambiguous consonants varying in f0 and voice onset time (VOT) was measured. The results suggest listeners adapt quickly to speaker-specific cues but also remain influenced by more global, naturally occurring covariance patterns of f0 and voicing in English. This pattern contrasts somewhat with studies where idiosyncrasy is represented instead by manipulation of primary, first-order cues to speech sounds, in which listeners are seen to adapt more straightforwardly to the cues they are presented.