Spoken Word Recognition of the Reduced American English Flap

Abstract

Phonetic variation as found in various speech styles is a rich area for research on spoken word recognition. Research on spoken word recognition has focused on careful, easily controlled speech styles. This dissertation investigates the processing of the American English Flap. Specifically, it focuses on the effect of reduction on processing. The main question asked in this dissertation is whether listeners adjust their expectations for how segments are realized based on speech style. Even more broadly, how do listeners process or recognize reduced speech? Two specific questions are asked that address individual parts of the broad question. First, how does reduction affect listeners’ recognition of words? Is it more difficult for listeners to recognize words pronounced in reduced forms, or is it perhaps easier for listeners to recognize reduced forms? Second, do listeners adjust their expectations about reduction based on preceding speech style (context)? Four experiments were designed using the auditory lexical decision and crossmodal identity priming tasks. Listeners’ responses to reduced and unreduced flaps (e.g. unreduced [pʌɾl] as opposed to reduced [pʌɾl]) were recorded. The results of this work show that the phonetic variation found in speech styles containing reduction causes differences in processing. Processing of reduced speech is inhibited by weakened acoustic information or mismatch to the underlying phonemic representation in the American English flap. Listeners use information about speech style to process the widely varying acoustic reflections of a segment in connected speech. The implications of these findings for models of spoken word recognition are discussed.