Speaking rate variability in spontaneous productions by non-native speakers

Abstract

Most research examining differences between native and non-native speech measures mean differences at the segmental level. Some work has examined non-segmental characteristics of speech such as speaking rate; however, this work has also typically examined only mean differences. In the present study, we ask whether within-speaker variability, in addition to mean differences, characterizes differences between non-native and native speech. Specifically, we examine speaking rate in spontaneous productions by both native and non-native speakers of English. Preliminary work suggests that rate change across utterances in read productions of non-native speech is more variable than in read productions of native speech (Baese-Berk and Morrill, 2014, Indianapolis ASA). However, it is possible that read speech contains sources of variability that are specific to processing difficulties during reading. In the present study, we examine native speakers of Korean and Mandarin producing spontaneous speech in English and compare their speech to both native speakers of English, and read productions by these same non-native speakers. We measure mean speaking rate within utterances, as well as the amount of rate change (slowing or speeding up of speaking rate) from utterance to utterance. Results will contribute to an understanding of the role of variability in non-native speech production.