Acoustic Characteristics of Patients' Speech Before and After Orthognathic Surgery

부정교합환자의 수술전.후 발음변화에 관한 음향학적 특성

It is reported that the orthognathic patients suffer from not only aesthetic problems but also resonance disorder and articulation disorder because of the abnormality of the oral cavity. This study was designed to investigate the resonance of nasality and the intelligibility of speech for acoustic characteristics of patients' speech before and after orthognatic surgery. 8 orthognathic patients participated in the study. The nasality of words containing Korean consonants, Korean consonants and frequency and intensity of the fricative /s/ were measured using Nasometer and CSL (Computerized Speech Lab). Results were as follows: First, the nasality of post orthognathic surgery patients decreased in spontaneous speech. There was a significant difference in the nasality for all words between pre and post orthognatic surgery patients. Second, the nasality of each Korean consonant phoneme of post orthognathic surgery patients decreased. There was also a significant difference of the nasality for each Korean consonant phoneme between pre and post orthognatic surgery patients. Third, the decreased nasality for Korean consonant phonemes showed in plosives, affricates, fricatives, liquids, and nasals after surgery. But the significant difference showed only in plosives and fricatives. Finally, frequency and intensity for the fricative /s/ of post orthognathic patients increased.