Fundamental frequency changes of Persian speakers across the life span.

This study was designed to investigate changes in fundamental frequency (F0) across the life span in Persian speakers. Four hundred children and adults were asked to produce a sustained phonation of vowel /a/ and their voice samples were studied in 10 age groups. F0 was analyzed using the software Praat (Version 5.1.17.). The results revealed that (1) the mean F0 in both sexes decreases from childhood to adulthood; (2) significant F0 differences between boys and girls begin at the age of 12 years; and (3) the range of F0 changes in the life span is greater in men (178.38 Hz) than in women (113.57 Hz). These findings provide new data for Persian-speaking children, women, and men and could be beneficial for Iranian speech and language pathologists.