Production and perception of vowel duration as a cue to the word‐final English /t/‐/d/ contrast by native and Chinese subjects

Abstract

Vowel duration was measured in seven minimally paired English words such as beat‐bead and bat‐bad as spoken by native English (NE) subjects and four groups of Chinese subjects (ten per group). The Chinese subjects were either relatively inexperienced (MA, TA) or experienced (TB) adult learners of English, or else had learned English as an L2 before the age of 12 years (TC). The early learners in TC closely resembled the NE speakers in making vowels much longer before /d/ than /t/. The inexperienced adult learners (MA, TA) produced a voicing effect, but one that was far smaller than that of the subjects in NE and TC. The experienced adult learners in TB produced a significantly larger voicing effect than the inexperienced subjects in TA and MA, but their effect was also smaller than that of the subjects in NE and TC. Sensitivity to vowel duration as a perceptual cue to the English /t/‐/d/ contrast was investigated in three ways. The subjects identified the members of natural continua in which vowel duration was varied by deleting glottal pulses. One continuum ranged from bead to beat, the other from bad to bat. The subjects imitated the members of both continua, and also chose which members of the continua represented the best exemplars of bead, beat, bad, and bat. As expected from the production data, the early learners in TC resembled the NE speakers perceptually, whereas the inexperienced adult learners (MA, TA) showed little evidence of perceptual sensitivity to vowel duration. Some experienced adult learners in group TB, on the other hand, were perceptually sensitive to the vowel duration cue. The relationship between their production and perception will be discussed.