[Quantitatively study of voice onset time-Glottal stop]

To quantitatively evaluate the acoustic characteristics of glottal stop, pronunciation of/ka/in 10 normal subjects and 14 patients with cleft palates were analyzed by sound spectrography and 20 msec in all normal articulation of /ka/ with an average time of 44.6 msec.In the test group of /ka/ demonstrated an average time of 20.8 msec.The inverse correlation ship between VOT and the psyco-acoustical judgment for the degree of distortion was demonstrated to be significant.