Perception of the oral-nasal distinction in vowels: A cross-language study

Cross-language research with isolated vowels has shown that accuracy of vowel discrimination, unlike consonant discrimination, is not affected by linguistic experience K. N. Stevens, A.M. Liberman, M. Studdert-Kennedy, and S. E. G. Öhman, Lang. Speech 12, 1–23 (1969). The present study extends cross-linguistic investigation of vowel perception to the oral-nasal contrast. Speakers of French, Hindi, and English were tested on identification and discrimination tasks using several oral-nasal vowel series to determine the effect of phonemic status of nasal vowels on accuracy of discrimination. (The contrast between oral and nasal vowels is phonemic in French and Hindi, but allophonic in English.) Stimulus materials were generated by articulatory synthesis and involved three 11-step /ba/-/bā/ series in which size of velopharyngeal port opening increased in equal increments from the oral to nasal endpoints. Results of three-step oddity discrimination tests for a series incorporating 2.4 sq mm increments showed similar performance for all three language groups. However, performance was generally poor for all subjects. The effect on discrimination accuracy of, two modifications in the series—increased discrimination step size and increased port aperture at the nasal end of the series—was investigated. Work supported by NICHD, NIMH.