Timing disturbances in the speech of a language-delayed Thai adult

Abstract

An acoustic-perceptual investigation was performed on various aspects of timing in the speech of a 21-year-old adult speaker of Thai who reportedly did not start speaking until the age of 7. Selected aspects of timing included: ( I ) the voicing contrast in Thai homorganic word-initial stops; (2) the duration contrast in Thai short and long vowels; and (3) the duration patterns of phrases and sentences in Thai connected speech. Measures of stop consonant voicing and vowel length were taken from monosyllabic citation forms; measures of syllables, phrases and sentences from an oral reading of a paragraph-sized passage. Findings indicated that speech timing skills relatcd to stop consonant voicing, vowel length, and rhythm can be differentially impaired, and moreover, that the pattern of impairment appears to be related to the size of the temporal planning unit.