Age and changes in vocal jitter.

Small cycle-to-cycle variations of voice fundamental frequency (vocal jitter) were examined for sustained phonations of vowels (/i,a,u/) produced by 20 young adults and 20 older adults. Jitter was measured by an automatic fundamental frequency tracking program which utilized a peak-picking method of voice analysis. Results showed that the average jitter of the older adults was significantly greater than that of the young adults. It was also found that the jitter magnitudes differed significantly among the vowels. Implications of the findings to aging effects on voice and early detection of laryngeal dysfunction were discussed.