Allophonic variation in American English

Abstract

It is well-known that two extremes of allophonic variations of voiceless stops serve as a cue to location of word boundaries. For example, the contrast between strongly aspirated and unaspirated /t/ is the primary difference in the utterances “grey tie” and “great eye”. If indeed such strong allophonic contrasts can be found in the few minimal pairs of word boundary that exist in English, it is reasonable to suspect a systematic pattern of variation of all consonants. Here we report a study of the consonants /t/, /d/, /n/, /l/ and /s/ from more than 20 min of reading, primarily by one speaker. We consider the devoicing time of /t/ and amplitudes of the other consonants, as functions of pausal, word, syllable and similar boundaries. The results show that the voiced portion of consonant tends to be low in amplitude and more consonantal in initial positions, and high in amplitude and more vocalic in final positions. The fricative portion of a consonant is more intense in initial positions and weaker in final ones.