Ability in perceiving nonnative contrasts: Performance on natural and synthetic speech stimuli

Abstract

The perception of the distinction between /r/ and /l/ by native speakers of American English and of Japanese was studied using natural and synthetic speech. The American subjects were all nearly perfect at recognizing the natural speech sounds, whereas there was substantial variation among the Japanese subjects in their accuracy of recognizing /r/ and /l/ except in syllable-final position. A logit model, which additively combined the acoustic information conveyed by F1-transition duration and by F3-onset frequency, provided a good fit to the perception of synthetic /r/ and /l/ by the American subjects. There was substantial variation among the Japanese subjects in whether the F1 and F3 cues had a significant effect on their classifications of the synthetic speech. This variation was related to variation in accuracy of recognizing natural /r/ and /l/, such that greater use of both the F1 cue and the F3 cue in classifying the synthetic speech sounds was positively related to accuracy in recognizing the natural sounds. However, multiple regression showed that use of the F1 cue did not account for significant variance in natural speech performance beyond that accounted for by the F3 cue, indicating that the F3 cue is more important than the F1 cue for Japanese speakers learning English. The relation between performance on natural and synthetic speech also provides external validation of the logit model by showing that it predicts performance outside of the domain of data to which it was fit.

The use of visual cues in the perception of non-native consonant contrasts

“…This variation in "perceptual skill" seen in a minority of L2 learners is not typically addressed in models of L2 acquisition. Studies of the relative weighting of acoustic cues to the /r/-/l/ contrast suggest that individuals vary widely in their reliance on different cues ͑e.g., Gordon et al, 2001;Iverson et al, 2005͒. Studies of the relative use of different acoustic cues to a phonemic contrast by native listeners also show that individuals may vary to the degree to which they make use of specific cues ͑Hazan and Rosen, 1991͒.…”

“…Despite these general effects, as in so many studies of L2 acquisition, there is strong evidence of individual variability in L2 perception in learners with similar exposure to the second language ͑e.g., Bradlow et al, 1997;Gordon et al, 2001͒, and of individual biases in the use of the auditory and visual modalities. This quite striking degree of individual variability is seen in the crossplots of individual results for the labial/labiodental contrast, with a small number of Japanese-L1 learners achieving ceiling performance in both the A and V conditions, while most Japanese-L1 learners were at near-chance level in both conditions.…”

“…The English phonemes /l/ and /r/ both tend to be assimilated, with variations in the goodness of fit, to the native alveolar flap, leading to problems in the discrimination and identification of these English phonemes ͑Bradlow et al, 1997, Iverson et al, 2003. The /l/-/r/ contrast is particularly difficult for Japanese learners because it is primarily marked by differences in third formant transitions to which Japanese listeners are not particularly sensitive, as they tend to give greater weight to more variable secondary cues such as F2 transition ͑Yamada, 1995; Iverson et al, 2003;Gordon et al, 2001;Lotto et al, 2004͒. In modern standard South Korean, a liquid is phonetically realized as an ͓1͔, ͓T͔, and ͓n͔. In intervocalic positions, a liquid becomes a flap ͓T͔, or becomes a lateral ͓l ͔ in intervocalic geminates.…”

Children’s Weighting Strategies for Word-Final Stop Voicing Are Not Explained by Auditory Sensitivities

“…In fact, most, if not all, of the signal components are commonly used in speech perception, although the amount of attention (i.e., weight) any one component receives can vary depending on numerous factors. In particular, native language background strongly affects the weighting of the various acoustic properties in the speech signal (e.g., Gordon, Keyes, & Yung, 2001;MacKain, Best, & Strange, 1981). For example, some languages do not permit syllable-final obstruents.…”

The significance of brain research for early intervention in childhood

“…Ein auffälliges Merkmal von erwachsenen Japanern beim Erlernen europä-ischer Fremdsprachen -und deshalb oft Gegenstand von Scherzen -ist die Schwierigkeit in der Aussprache, die Phoneme "r" und "l" klar zu trennen [14,18]. Dazu muss man wissen, dass -akustisch gesehen -die verschiedenen Frequenzelemente, die diese Phoneme bilden, durch leichte Ände-rungen kontinuierlich von "r" nach "l" transformierbar sind.…”