Identifying linguistic contributions to variable speech perception in Spanish/English bilingual children and adults using the ascending target-to-masker ratio method

Abstract

When people encounter variable speech, like an unfamiliar accent, they map new productions to existing word forms. This skill appears to develop through adolescence for monolingual children, with school-age children perceiving unfamiliar accented speech less accurately than adults. For monolingual children, vocabulary size and phonemic awareness predict performance. Less is known about which factors account for individual differences in variable speech perception in multilingual school-age children. The goals of this study were to (a) assess group differences in variable speech perception in Spanish/English bilingual and English monolingual children and adults, (b) validate the ascending target-to-masker (TMR) method for assessing speech reception thresholds (SRTs) for foreign accented speech, and (c) identify linguistic skills that account for individual differences in performance. Participants completed speech perception and language testing. SRTs in speech-shaped noise were measured for Midland-, Spanish-, and Korean-accented English; these accents ranged from familiar to unfamiliar across participants. In each accent condition, one list of Bamford-Kowal-Bench test sentences was presented, with each sentence presented at multiple TMRs. Preliminary data suggest differences in how bilingual and monolingual groups perceive variable speech in noise. While linguistic skills accounted for individual differences in performance, different patterns emerged in children and adults.