Acoustic changes in voice after surgery for snoring: preliminary results

All surgical procedures for treatment of snoring and obstructive sleep apnoea modify the anatomical structure of the upper airways and the resonance characteristics of the vocal tract; this can lead to a modification in voice quality. Purpose of this study was to evaluate the possible modifications of the fundamental frequency (F0) and of the frequency and amplitude of the first (F1) and second (F2) formants of the 5 Italian vowels after different surgical procedures for snoring, to verify if and how these operations can influence voice quality. A total of 40 snoring or obstructive sleep apnoea syndrome patients, not affected by laryngeal, pulmonary or neurologic disorders likely to alter voice production, were selected for the study. All were submitted to acoustic voice analysis prior to surgery and again 1 month after discharge. F0 was unchanged. The frequency of F1 of the vowel /a/ audio of F2 of the vowel /e/ were significantly higher, while F1 of /i/ and F2 of /o/ and /u/ were significantly lower compared to pre-operative values. The modifications in the anatomical structure and volume of the vocal tract, induced by the surgical procedures used for the treatment of snoring, can modify the values of the formants and, as a consequence, quality of the voice. This change can be detected not only by means of the acoustic analysis but also by the patient itself. For this reason, singers and all professional voice users about to undergo surgical treatment for snoring should be informed of this potential modification of the voice not only for clinical reasons but also for legal purposes.