title: Phonetic variation in consonants in infant-directed and adult-directed speech: the case of regressive place assimilation in word-final alveolar stops.
abstract: Pronunciation variation is under-studied in infant-directed speech, particularly for consonants. Regressive place assimilation involves a word-final alveolar stop taking the place of articulation of a following word-initial consonant. We investigated pronunciation variation in word-final alveolar stop consonants in storybooks read by forty-eight mothers in adult-directed or infant-directed style to infants aged approximately 0;3, 0;9, 1;1, or 1;8. We focused on phonological environments where regressive place assimilation could occur, i.e., when the stop preceded a word-initial labial or velar consonant. Spectrogram, waveform, and perceptual evidence was used to classify tokens into four pronunciation categories: canonical, assimilated, glottalized, or deleted. Results showed a reliable tendency for canonical variants to occur in infant-directed speech more often than in adult-directed speech. However, the otherwise very similar distributions of variants across addressee and age group suggested that infants largely experience statistical distributions of non-canonical consonantal pronunciation variants that mirror those experienced by adults.
authors: Department of Communicative Sciences and Disorders, Department of Psychology, Department of Linguistics and Germanic, Slavic, Asian and African Languages, Michigan State University.
authors: Laura C
authors: LC
authors: Dilley
authors: Department of Communication Sciences and Disorders, University of Missouri.
authors: Amanda L
authors: AL
authors: Millett
authors: Department of Psychology, Michigan State University.
authors: J Devin
authors: JD
authors: McAuley
authors: Department of Otolaryngology - Head & Neck Surgery, Indiana University School of Medicine.
authors: Tonya R
authors: TR
authors: Bergeson
mesh_terms: D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009034:Mother-Child Relations; D010700:Phonetics; D013061:Speech Acoustics; D013068:Speech Production Measurement