A radiographic analysis of constriction locations for vowels

Vocal tract area functions estimated from 38 sets of X-rayed vowel articulations collected from the literature and from new X-ray motion films of English and Arabic speech reveal four constriction locations: along the hard palate, along the soft palate, in the upper pharynx and in the lower larynx. Each location is appropriate for a definable class of vowel qualities, confirming the quantal nature of at least this aspect of vowel articulation. The acoustical, physiological and phonological implications are discussed. In a given phonotactic environment the precision of the constricting tongue manoeuvre was good. The only truly language specific difference was a preference for either the midpalatal or prepalatal location for palatal constrictions. The tongue muscles are found to be admirably situated for creating constrictions at the four locations.