Investigation of Formant Structure in Azeri Language Vowels in Azeri Adults Aged 18-24 Years Old

Formant structure is the most important acoustic characteristic of vowels and the vowel is the main center of syllables. Therefore, an investigationof their formants structure is of great importance.The aim of the present study was to investigate the nine Azeri vowel's formants.
The present study was a cross-sectional and descriptive-analytic study. The participants of this study were 50 (25 males-25 females) students of Tabriz University of Medical Sciences with their age ranging from 18-24 years old. The fundamental frequency (F0) of /a/ and /i/ vowels and the first, second, and third formants (F1, F2, F3) of nine Azeri vowels were determined with using Praat software. Statistical analysis was performed with SPSS software. When the data were normally distributed, independent t-test was used. Otherwise, Mann-Whitney test was used.
F0 of /a/ and /i/ vowels are significantly higher in females than males. /æ/ and /i/ vowels in the both sexes, respectively, have the most and least F1. The most F2 in the both sexes is /i/ and the least F2 in male /æ/ and in females is /o/. Also, in both sexes, the most F3 is /i/ vowel and the least F3 is /ø/ vowel.
/æ/ and /i/ vowels in the both sexes, respectively, are the most open and closed vowels. /i/ vowel in the both sexes and /æ/ in males and /o/ in females respectively, are the most front and most back vowels. The roundest vowel in Azeri is /ø/ and the most spread vowel is /i/.