Effects of noise and speaker's language background on plosive perception

Abstract

This study examined the effect of speakers' language background and noise on the perception of American English (AE) plosives. Six normal-hearing, young-adults volunteered for the study. Participants listened to speech tokens of six plosives, /p/, /b/, /t/, /d/, /k/, and /g/ in the initial, medial, and final positions in the context of three vowels, /a/, /i/, and /u/, spoken by native Bangladeshi Bengali (BB) and AE speakers. Tokens were presented at 45, 65, and 65 dB SPL, either in quiet or noise. Multitalker babble, speech noise, and 1000–2000 Hz, 2000–4000 Hz, and 500–5000 Hz noise bands were used as noise. Significant differences were found with all noise types across both language backgrounds; the most difficult noise type condition being the multitalker babble. Listeners performed the best at 65 dB SPL. Listeners perceived plosives spoken by AE than BB speakers with significantly greater accuracy, more so in noise, except in the final positions. For BB-spoken tokens, listeners had the most difficulty with voicing and aspiration features. Voiceless sounds were easily confused with voiced, especially in the initial positions. This study has significant implications for accent reduction therapy as well as for teaching English to English Language Learner's. Further studies are warranted.