An acoustic description of spectral and temporal characteristics of Azerbaijani vowels

This paper presents an acoustic description of the nine Azerbaijani vowels; investigating the underlying acoustic and temporal characteristics of its vowel system. We explored acoustic and temporal parameters including: the first three formants (F1, F2 and F3), fundamental frequency (F0) and duration of the vowels. Participants in this study were 20 male and 23 female Azerbaijani speakers with a Tabrizi dialect. They were asked to utter three repetitions of the nine Azerbaijani vowels in three natural word contexts, embedded in carrier sentences. Results showed that the [ɯ] and [œ] vowels had a large overlap in the F1–F2 vowel space. Further analysis suggested that F3 is an important cue in discrimination of this vowel pair. Vowel-intrinsic duration effect seemed to be relatively strong in Azerbaijani. Other universal features also were found in the production of Azerbaijani vowels: low vowels and female speakers had lower F0 values. Surprisingly, in contrast with previous results for most languages, the average duration of Azerbaijani vowels was greater in males than females. The results of this study define the acoustic vowel-space of the Azerbaijani language and develop a database for further comparisons and investigations.