Acoustic salience in the evaluations of intelligibility and foreign accentedness of nonnative vowel production

Abstract

The study investigates the relative weighting of spectral and temporal acoustic cues in native speakers’ (NS) perception of vowels produced by nonnative speakers (NNS). Acoustic measurements were taken of the spectral and temporal properties of vowels produced by Chinese L2 speakers of English, and by native speakers of American English and British English, who were recruited to pronounce monosyllabic words containing 18 monophthongs and diphthongs in English. In the perception experiment, 25 native English speakers (16 American and 9 British) provided evaluations of intelligibility and ratings of foreign accentedness of the non-native vowels. A correlation analysis was conducted between the NS perception results and the acoustic computation of the NNS production data. The results show that spectral properties of vowels are significantly related to both American and British speakers’ evaluation of English vowels produced by Chinese L2 speakers, whereas the temporal information has no significant correlation to NS perceptual evaluations. The correlation between acoustic measurements and perceptual evaluations confirms that the most significant acoustic cue of English vowels is spectral rather than temporal information in perception.