title: The use of ultrasound in the study of articulatory properties of vowels in clear speech.
abstract: Although the acoustic properties of clear speech have been extensively studied, its underlying articulatory details have not been well understood. The purpose of the present study is twofold: To examine the specific articulatory processes of clear speech using ultrasound and to investigate whether and how the type of listener (hard of hearing, normal hearing) and the lexical property of words (frequency) interact in the production of clear speech. To this end, we examined productions of /ɑ/, /æ/ and /u/ from 16 speakers of US English. Overall, our ultrasound results suggested that the tongue's highest point moved in a direction that exaggerated the three vowels' phonological features, resulting in an expanded articulatory vowel space for the hard-of-hearing listener and low-frequency words. No interaction was found between the listener and word frequency, suggesting that the effects of word frequency hold constant across the two types of listeners.
authors.affiliation: a Department of Linguistics , University of Wisconsin-Milwaukee , Milwaukee , WI , USA.
authors.forename: Jae Yung
authors.initials: JY
authors.lastname: Song
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D013060:Speech / Q000502:physiology*; D013061:Speech Acoustics; D013065:Speech Intelligibility / Q000502:physiology*; D013067:Speech Perception; D014463:Ultrasonography / Q000379:methods*
keywords: Acoustics; articulation; clear speech; ultrasound; vowels