Could formant frequencies of snore signals be an alternative means for the diagnosis of obstructive sleep apnea?
OBJECTIVE: To study the feasibility of using acoustic signatures in snore signals for the diagnosis of obstructive sleep apnea (OSA). METHODS: Snoring sounds of 30 apneic snorers (24 males; 6 females; apnea-hypopnea index, AHI=46.9+/-25.7events/h) and 10 benign snorers (6 males; 4 females; AHI=4.6+/-3.4events/h) were captured in a sleep laboratory. The recorded snore signals were preprocessed to remove noise, and subsequently, modeled using a linear predictive coding (LPC) technique. Formant frequencies (F1, F2, and F3) were extracted from the LPC spectrum for analysis. The accuracy of this approach was assessed using receiver operating characteristic curves and notched box plots. The relationship between AHI and F1 was further explored via regression analysis. RESULTS: Quantitative differences in formant frequencies between apneic and benign snores are found in same- or both-gender snorers. Apneic snores exhibit higher formant frequencies than benign snores, especially F1, which can b
