A meta-analysis of vowel formants in Turkish: Methodological differences and their impacts

Authors

Ali Cagan Kaya
Hacettepe University
https://orcid.org/0009-0007-9386-9766
Emre Yagli
Hacettepe University
https://orcid.org/0000-0002-1044-9018

Synopsis

Although research on vowel formants in Turkish constitutes a substantial body of work, there is a lack of methodological consensus among these studies. This study presents a meta-analysis examining methodological differences in research on vowel formants in Standard Turkish and the effects of these differences on formant values. Within the scope of this study, 16 studies on Standard Turkish were adopted, and the methodological criteria of these studies were coded in a data table to create the dataset. In the data analysis, separate mixed-effects models were fitted for each vowel in the R environment. The results indicated that random effects (e.g., study and study-vowel interaction) in the models were statistically more determinant in explaining variability compared to fixed effects (e.g., gender, material type, number of speakers, recording environment, recording equipment, sampling rate, and normalisation method). This finding indicates that variability in formant values largely stems from implicit methodological choices that are neither clearly reported nor standardised across studies. The study emphasises the necessity of methodological transparency, open data sharing, and standardised measurement protocols to ensure the reliability and comparability of phonetic descriptions in Turkish.

Keywords: Vowel formants, Phonetic description, Meta-analysis, Methodology

Author Biographies

Ali Cagan Kaya, Hacettepe University

Ali Çağan Kaya is a high-honors undergraduate researcher in the Department of English Linguistics at Hacettepe University. His primary research interests encompass experimental phonetics (acoustic phonetics), psycholinguistics, and computational tool development. His research focuses specifically on Turkish vowel formants, employing experimental methods such as eye-tracking and pupillometry. He served as a research intern at the Ankara University Brain Research Center (AU-BRC), where he acquired proficiency in complex data modeling utilizing computational tools and environments like Praat, R (LMM, GAMM), and Python. He is currently executing a project titled "The Vowel Frequencies of Standard Turkish," funded by the TÜBİTAK 2209-A program. To provide methodological contributions to the literature, he has developed open-source software, including "VowSpace" (a vowel formant analysis and normalization tool) and the AI-powered "Praanscribe" (a semi-automatic segmentation tool for Praat). Furthermore, he is the co-author of a meta-analytical chapter on Turkish vowel formants in the volume Contemporary Studies in Linguistics I. Alongside his experimental research, he also serves as the President of the Hacettepe University Linguistics Community.

Emre Yagli, Hacettepe University

Assoc. Prof. Dr. Emre Yağlı is a faculty member in the Department of English Linguistics at Hacettepe University. He received his B.A. (2009), M.A. (2012), and Ph.D. (2018) degrees from Hacettepe University.His doctoral research focused on sociophonetic variables and listener perceptions in Turkish. His research interests include sociolinguistics, the interface between phonetics/phonology and sociolinguistics, language ideologies, and discourse analysis. He has published widely in national and international peer-reviewed journals and has contributed book chapters on language variation and social meaning.

Published

December 31, 2025

How to Cite

Kaya, A. C., & Yagli, E. . (2025). A meta-analysis of vowel formants in Turkish: Methodological differences and their impacts. In O. Cinar, F. Başbuğ, & H. Aydemir (Eds.), & (Ed.), Contemporary Studies in Linguistics I (Vol. I, pp. 170-192). Artsurem Publishing. https://doi.org/10.7816/imuling-15-2025-01X008