American English Phonetics

4.1.2 Stylistic variants

It is frequently the case that the pronunciation of a phoneme depends on the speech style. That is, the realization of the phoneme is different in formal styles than in in informal style. For example, in ordinary, conversational styles, GA /t/ is pronounced without release in final position. Say the Dutch word kat: notice how the last consonant ends with a very weak [s]-like sound. This is because the closure that your tongue made with the teeth ridge is released when the air pressure behind the closure is still sufficiently high for the air to escape audibly from the mouth. In GA, such audible releases are only used in very formal styles, such as when a teacher were to pronounce the word cat in front of a class. That is, in utterance-final positions, both released [t] and unreleased [t] are used, but released [t] only occurs in formal styles. Such stylistic variants of the same phoneme are traditionally called free variants, which label is perhaps somewhat misleading, because the variation is not ’free’ but conditioned by speech style. Hence the term stylistic variants.