Speaker specificity in speech perception: the importance of what is and is not in the signal

Abstract

In some American English dialects, /ae/ before /g/ (but not before /k/) raises to a vowel approaching [E], in effect reducing phonetic overlap between (e.g.) ‘‘bag’’ and ‘‘back.’’ Here, participants saw four written words on a computer screen (e.g., ‘‘bag,’’ ‘‘back,’’ ‘‘dog,’’ ‘‘dock’’) and heard a spoken word. Their task was to indicate which word they heard. Participants’ eye movements to the written words were recorded. Participants in the ‘‘ae-raising’’ group heard identity-spliced ‘‘bag’’-like words containing the raised vowel [E]; participants in the ‘‘control’’ group heard cross-spliced ‘‘bag’’-like words containing standard [ae]. Acoustically identical ‘‘back’’-like words were subsequently presented to both groups. The ae-raising-group participants identified ‘‘back’’-like words faster and more accurately, and made fewer fixations to the competitor ‘‘bag,’’ than control-group participants did. Thus, exposure to ae-raised realizations of ‘‘bag’’ facilitated the identification of ‘‘back’’ because of the reduced fit between the input and the altered representation of the competing hypothesis ‘‘bag.’’ This demonstrates that listeners evaluate the spoken input with respect to what is, but also what is not, in the signal, and that this evaluation involves speaker-specific representations. [Work supported by NSF Human and Social Dynamics 0433567.]