Vowel perception in quiet and noise for native and non-native listeners: Analysis of vowel identifiability

Abstract

For a number of years, research on phonetic perception has been primarily focused on the percentage correct of phonetic identification (e.g., hit rate) without considering listeners’ response (e.g., false alarm). The purpose of this study was to compute d’ of English vowel identification in quiet and noise including both hit rate and false alarm for native and non-native listeners. Both data analyses showed native listeners outperformed non-native listeners for vowel identification in quiet and noise. However, the d’ data showed that the non-naïve disadvantage became larger in long-term speech shaped (LTSS) noise than in quiet, while the percentage correct data showed an oppositely finding that the non-native disadvantage was smaller in LTSS noise than in quiet. These preliminary results suggest that false alarms should be included in the data analysis of phonetic perception and the idenitificability (e.g., d’) based on the signal detection theory may be more appropriate to evaluate listeners’ capacity to identify phonemes. [Work supported by China Natural Science Foundation 31628009 and University of Texas at Austin Research Grant].