Volumetric measurements of vocal tracts for male speakers from different races.

Research examining physiologic and acoustic characteristics of culturally diverse populations is sorely needed, but rarely reported. The major aim of this study was to quantify vocal tract dimensional parameters (oral length, oral volume, pharyngeal length, pharyngeal volume, total vocal tract length and total vocal tract volume) of adult male speakers from three different racial populations (White American, African American, and Chinese). It also attempted to investigate if volumetric differences in the speakers' vocal tracts, like length differences, would contribute to the acoustic characteristics of these speakers from different races. The findings of this study support the hypothesis that speakers from different races may have morphological differences in their vocal tract dimensions, and these morphological differences (especially volumetric differences) could be partially responsible for the formant frequency differences in a vowel sound void of specific language/dialectal impacts. The study has provided speech scientists, speech-language pathologists, linguists and other health professionals with a new and preliminary acoustic and physiological database for adult male speakers from these three different races.