Degree of foreign accent in native Japanese speakers trained in non-native phonetic contrast discrimination

Degree of foreign accent was evaluated in nine native Japanese speakers who participated in a behavioral training program to increase accuracy of perception of a non-native consonantal contrast. For all subjects, speech samples were collected after perceptual training. Additional pretraining samples were also collected from a subset of subjects. Subjects were asked to produce six sentences describing a set of visual images portraying people and objects. Images were chosen to elicit production of /r/ and /l/ sounds in different vowel context and word positions. Sentences produced by two native American English speakers were also recorded. A group of ten native American English speakers listened to digital recordings of all speakers’ sentences, randomly presented via computer, and rated them for degree of foreign accent on a seven-point scale. Each Japanese speaker’s scores were averaged and then correlated with their performance on discrimination of /r/ and /l/ before and after training, as well as with results from a functional magnetic resonance imaging study in which the same subjects participated [Doeleman et al., J. Acoust. Soc. Am. 107, 2803 (2000)]. These comparisons reveal how differences in degree of foreign accent correspond to behavioral and neuroimaging data. [Work supported by NICHD HD37954 to P.K.K.]