A Comparative Study of Persian Vowel Quality in the Speech of 18-28 Year Old Turkish Speakers

Formant structure is an important feature of vowels in any language. The formant structure of any vowel can be a function of gender. This study investigated the formant structure of six Persian vowels used in the speech of Turkish speakers aged 18-28 years old.
This is a descriptive-analytic cross-sectional study. A total of 30 male (N=15) and female (N= 15) 18-28 year old participants were recruited from among Turkish speaking students studying at Iranian University of Medical Sciences. The fundamental frequency and three first formants of each of six Persian vowels were recorded by Praat software. Independent samples-t test and Mann U Whitney were used to analyze the data.
Among male participants, the lowest fundamental frequency was related to /æ/ vowel with a mean of 120 Hz, the highest being /i/ vowel with a mean of 128 Hz. The lowest first formant was related to /i/ vowel with a mean of 280 Hz, the highest being /æ/ vowel with mean of 693 Hz. The highest second formant was related to /o/ vowel with a mean of 931 Hz, the lowest being /i/ vowel with mean of 2135 Hz. The lowest third formant was related to /æ/ vowel with mean of 2554 Hz, the highest being /i/ vowel with mean of 2927 Hz. Among the female participants, the lowest fundamental frequency was related to /æ/ vowel with mean of 219 Hz, the highest being /i/ vowel with mean of 249 Hz. The lowest first formant was related to /i/ vowel with mean of 348 Hz, the highest being /æ/ vowel with mean of 943 Hz. The lowest second formant was related to /u/ vowel with mean of 771 Hz, the highest being /i/ vowel with mean of 2686 Hz. The lowest third formant was related to /æ/ vowel with mean of 2815 Hz, the highest being /i/ vowel with mean of 3303 Hz. All the differences between male and female participants were significant except for the first and third formant in /u/ vowel, second formant in /o/ vowel and third formant in /a/ vowel (p It can be concluded gender is not only a factor for a differences of fundamental frequency, but it also can account for differences in vowel space of Persian vowels in the speech Turkish male and female speakers. It seems that the significant greater amount of fundamental frequency of all of vowels in females can be the result of smaller dimensions of larynx, and smaller length and mass of vocal tract, though part of this difference may be a function of other factors such as language or dialect. The significant greater amount of first formant of female participants shows the higher position of tongue in females during production of the vowels. Reduction in second formant with more posterior vowels shows the smaller distance between the narrowest place of articulators and larynx. Vowel space in female participants was greater than that in males, obviously in front vowels. Therefore, it seems necessary to replicate this study in some other languages or dialects for closer study of gender's effect and other factors such as language or dialect.