Middle Eastern Journal of Disability Studies

Abstract
Background and objective: Time based analysis methods are limited by many factors; however, as the resent research shows, the frequency based methods are more sensitive to voice perturbations. The objective of the present study was to evaluate Cepstral peak prominence (CPP) and Smoothed Cepstral Peak Prominence (CPPS) of normal male and female Persian speakers.
Methods: A cross sectional comparative method was used to evaluate and compare normal female Persian speakers’ sustained vowel prolongation. The participants were 200 male and female Persian speakers in equal numbers. Comfortable loudness and standard text reading were used as tasks. The acoustic analysis to calculate CPP and CPPS was performed by Speech Tool software. Independent T-test was used to analyze the data.
Results: Mean values of CPPS in male group were significantly higher in both vowel prolongation and text reading tasks than among female participants (p<0.05); while, the amount of CPP was just higher in only text reading task (p<0.05).
Conclusion: Voice quality of normal males Persian speakers is better than that of normal females. This finding may be explained by posterior phonatory gap as a common anatomic pattern in Iranian female population. It is also evident that CPP and CPPS are sensitive enough to be used for the assessment of voice quality in Iranian population.