Abstract:

This study completes an investigatation of pitch discrimination during breathy phonation versus modal phonation by manipulating acoustic parameters. Both breathy vowels and modal vowels from Jalapa Mazatec were digitized. Intensity was equalized, and F0 was manipulated by approximately 3-Hz increments (up to 12 Hz) employing the SOUNDEDITPRO16 sound editing program; all other acoustic parameters were held constant. Ten subjects each listened to 1000 pairs of these stimuli and judged whether they were the same or different. Subjects performed more accurately on modal vowel pairs than on breathy vowel pairs. Moreover, at the 3- and 6-Hz intervals, the difference between performances on modal pairs versus breathy pairs was significantly greater than the difference between modal pairs versus breathy pairs at the 9- and 12-Hz intervals. This indicates that, although frequency distinctions increase linearly in both phonation groups, a nonlinear discriminability relationship exists within each group.