Many Investigators have studies the acoustic properties of pathologic voice with various techniques, such as aerodynamic, glottographic, acoutic, electromyographic and fiberscopic analysis. Among the above methods, Acoustic analysis has been used at recent, and pitch pertubation has showed a significant correlation with the psychophysical measurement of the degree of the hoarseness. So authors feel that the normal phenomenons of the pitch pertubation for the various sustained vowel sounds are important, and report the jitter distributions, jitter ratio, jitter index and mean jitter for the normal male subjects with a review of literature.