Lexically specific accumulation in memory of word and segment speech rates

Variability abounds in speech. According to usage-based accounts, lexical representations reflect phonetic variants of words resulting from contextual conditioning. Because faster speech contexts promote durational shortening of words and segments, words that occur more often in fast speech may be more reduced than words commonly used in slow speech, independent of the target’s contextual speech rate. To test this, linear mixed-effects models including a word form’s ratio of conditioning by fast speech contexts (FRCRATE) are used to predict the duration of Spanish /s/ and words containing /s/ in a corpus of spoken Spanish. Results show that words’ cumulative exposure to relatively fast speech affects phonetic realizations independent of factors operative in the production contexts. Thus, word and segment rates reflect cumulative (lexicalized) effects of words’ experience in fast speech contexts. The results suggest that lexically specific cumulative measures should be incorporated into models of linguistic variation and change.