Individual differences in the perception of final consonant voicing among native and non-native speakers of English

In two previous papers published in Journal of Phonetics, we presented findings concerning perception and production of devoicing by native speakers of Mandarin (Hayes-Harb, Smith, Bent, & Bradlow, 2008) and native speakers of German (Smith, Hayes-Harb, Bruss, & Harker, 2009), who were learning English as a second language (L2). As with most studies dealing with the acquisition of L2 speech perception and production, we reported findings concerning general patterns among the various groups of listeners and speakers. We have subsequently come to appreciate that although averages across groups of subjects allow for useful generalizations, it is important to be cautious in drawing strong conclusions about the nature of L2 speech perception and production based only on group data, e.g., inferring that all subjects show essentially the same pattern as represented by group averages. The purpose of the present investigation was to re-examine speech perception patterns for the English word-final voicing contrast among the native English and non-native speakers/listeners from the Hayes-Harb et al. (2008) and Smith et al. (2009) studies in greater detail and to emphasize the importance of evaluating the performance of individual listeners along with group data in future research.

Research highlights
► Individual performance should be considered in evaluating L2 speech perception.
► “Patterns” based on averages can conceal quite variable performance among subjects.
► Many L2 subjects show little evidence of an inter-language speech intelligibility benefit.