Statistical distributions of consonant variants in infant-directed speech: Evidence that /t/ may be exceptional

Publication date: July 2019Source: Journal of Phonetics, Volume 75Author(s): Laura Dilley, Jessica Gamache, Yuanyuan Wang, Derek M. Houston, Tonya R. BergesonAbstractStatistical distributions of phonetic variants in spoken language influence speech perception for both language learners and mature users. We theorized that patterns of phonetic variant processing of consonants demonstrated by adults might stem in part from patterns of early exposure to statistics of phonetic variants in infant-directed (ID) speech. In particular, we hypothesized that ID speech might involve greater proportions of canonical /t/ pronunciations compared to adult-directed (AD) speech in at least some phonological contexts. This possibility was tested using a corpus of spontaneous speech of mothers speaking to other adults, or to their typically-developing infant. Tokens of word-final alveolar stops – including /t/, /d/, and the nasal stop /n/ – were examined in assimilable contexts (i.e., those followed by a word-initial labial and/or velar); these were classified as canonical, assimilated, deleted, or glottalized. Results confirmed that there were significantly more canonical pronunciations in assimilable contexts in ID compared with AD speech, an effect which was driven by the phoneme /t/. These findings suggest that at least in phonological contexts involving possible assimilation, children are exposed to more canonical /t/ variant pronunciations than adults are. This raises the possibility t...
Source: Journal of Phonetics - Category: Speech-Language Pathology Source Type: research