The aim of this study is to determine the sound characteristics of speech sounds of patients applied to orthodontics clinic to understand how speech will be affected after orthodontic treatment. The study included 60 patients (35 females, 25 males; 13.60±2.35 years) Fricatives (/f/, /s/, /ş/) were selected for spectral center of gravity analysis. Sounds were examined under four groups: syllable-initial, syllable-final, /a/ context and /i/ context. The Shapiro Wilk test and Mann-Whitney U-test, were used for statistical evaluations. There was a statistically significant difference between syllable-initial and syllable-final measurements of /f/ sound (p=0.008). There was a significant effect of gender in all groups of /s/ sound and syllable-initial group of /ş/ sound (p
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Jesus LMT, Araújo A, Costa IM. Speech production in two occlusal classes. Onomázein. 2014;29:129-51.
Johnson NC, Sandy JR, Tooth position and speech—is there a relationship?. Angle Orthod. 1999;69:306-10.
Ladefoged P. Vowels and consonants: An introduction to the sounds of languages. 1st edition. Blackwell Publishers, Oxford, 2001.
Yavuz H, Balcı A. Turkish Phonology and Morphology (Türkçe Ses ve Biçim Bilgisi). Anadolu Üniversitesi Yayınları, Eskişehir, 2011;15-33.
Fry DB. The physics of speech. Cambridge University Press, Cambridge, 1979.
Forrest K, Weismer G, Milenkovic P, et al. Statistical analysis of word-initial voiceless obstruents: preliminary data. J Acoust Soc Am. 1988;84:115-23.
Gordon M, Barthmaier P, Sands K. A cross-linguistic acoustic study of voiceless fricatives. J Int Phon Assoc. 2002;32:141-74.
Jongman A, Wayland R, Wong S. Acoustic characteristics of English fricatives. J Acoust Soc Am. 2000;108:1252-63.
Ertan E. Türkçe’deki Sürtünmeli Seslerin Akustik Özelliklerinin Belirlenmesi. Ph.D. thesis, Anadolu University, Eskişehir, 2011.
Ladefoged, P. Phonetic data analysis: An introduction to fieldwork and instrumental techniques. Blackwell Publishing, Oxford, 2003;138-69.
Tabain M. Variability in fricative production and spectra: Implications for the hyper-and hypo-and quantal theories of speech production. Lang Speech. 2001;44:57-94.
Nittrouer S, Studdert-Kennedy M, McGowan RS, The emergence of phonetic segments: Evidence from the spectral structure of fricative-vowel syllables spoken by children and adults. J Speech Hear Res. 1989;32:120-32.
McFarland DH, Baum SR, Chabot C. Speech compensation to structural modifications of the oral cavity. J Acoust Soc Am. 1996;100:1093-104.
Hughes GW, Halle M. Spectral Properties of Fricative Consonants. J Acoust Soc Am. 1956;28:303-10.
Koenig LL, Shadle CH, Preston JL, et al. Toward improved spectral measures of /s/: results from adolescents. J Speech Lang Hear Res. 2013;56:1175-89.
Munson B. A method for studying variability in fricatives using dynamic measures of spectral mean. J Acoust Soc Am. 2001;110:1203-6.
Nittrouer S. Children learn separate aspects of speech production at different rates: Evidence from spectral moments. J Acoust Soc Am. 1995;97:520-30.
Nirgianaki E. Acoustic characteristics of Greek fricatives. J Acoust Soc Am. 2014;135:2964-76.
Lubit EC. The relationship of malocclusion and faulty speech articulation. J Oral Med. 1967;22:47-55.