The effect of adventitious deafness on the perception and production of voice onset time in Thai: A case study

The perception and production of voice onset time (VOT) was investigated in a Thai patient with an adventitious, profound sensorineural heating loss. Thai exhibits a three-category voicing distinction for bilabial (/b, p, p^h/) and alveolar (/d, t, t^h/) stops, and a two-category distinction for velar (/k, k^h/) stops. VOT perception was measured in labeling responses to synthetic speech continua differing in VOT; VOT production was measured in word-initial stops of words produced in isolation. These measurements were compared with previously published VOT data for normal-hearing Thai speakers. The results of acoustic analyses of this subject's productions suggested only minor articulatory perturbations, and the target phonemes were generally identified accurately by normal listeners.