Identification of Down's syndrome adults from prolonged vowel samples.

Special educators and speech pathologists were both able to distinguish adults with Down's syndrome from nonretarded adults with voice disorders based only on prolonged vowel samples. Listeners indicated that resonance differences may have helped them to identify Down's syndrome speakers. Differences in formant frequencies and perceived hypernasality between Down's syndrome and nonretarded speakers, however, were nonsignificant. Formant frequency measures and perceived nasality ratings obtained from Down's syndrome adults in the present study are in contrast to such measures obtained from Down's syndrome children in previously reported studies.