Effects of Frequency, Intensity, and Vowel-Type Variations on Maximum Phonation Time

Abstract

Forty adult subjects, 20 males and 20 females, performed 14 maximum phonation time tasks: sustained phonations of /a/ using soft, moderate, and loud intensity levels at the 25th, 50th, and 75th percentile points in the subject's pitch range; sustained phonations of /i/, /u/, and /æ/ using a moderate intensity level at the 50th percentile point in the subject's pitch range; and two uncontrolled phonations. It was found that (1) for low-frequency phonations, subjects showed a progressive increase in phonation time with an increase in intensity level; (2) for high-frequency phonations, subjects exhibited a progressive decrease in phonation time with an increase in intensity level; (3) for moderate-frequency phonations, the male group showed a progressive increase in phonation time with an increase in intensity level, while the female group exhibited a greater phonation time for the soft than for the loud intensity level conditions; and (4) subjects exhibited the longest phonation time for /i/ and the shortest time for /æ/. These results indicate that frequency, intensity, and vowel-type variations should be taken into consideration in all tasks involving maximum duration of phonation. [Research supported by the National Institute of Neurological Diseases and Blindness.]