14th International Congress of Phonetic Sciences (ICPhS-14)

San Francisco, CA, USA
August 1-7, 1999

Vowel Length, Post-Vocalic Voicing and VOT in the Speech of Two-Year-Olds

Carol Stoel-Gammon (1), Eugene H. Buder (2)

(1) University of Washington, Seattle, USA; (2) The University of Memphis, Memphis, USA

The present study examines speech timing in the productions of 20 normally developing two-year-olds acquiring American English. Monosyllabic CVC forms were elicited in a naturalistic procedure, providing 927 tokens that were digitized and subjected to acoustic and perceptual analysis. The main measures included (a) extrinsic and intrinsic vowel durations of tense and lax high front vowels in CVC words; (b) voicing of the final obstruent; and (c) the voice onset time (VOT) of word-initial stops. Findings revealed that (a) about half the children exhibited statistically reliable differences in extrinsic (i.e., contextsensitive) vowel durations, but fewer than 15% exhibited statistically reliable differences in intrinsic vowel durations; (b) 70% of the children tended to devoice word-final voiced obstruents; and (c) 50% of the children exhibited stable VOT contrasts for word-initial stops. Group trends and individual patterns of speech timing are discussed.

Full Paper

Bibliographic reference.  Stoel-Gammon, Carol / Buder, Eugene H. (1999): "Vowel length, post-vocalic voicing and VOT in the speech of two-year-olds", In ICPhS-14, 2485-2488.