ACOUSTIC ANALYSIS OF SNORING SOUND IN PATIENTS WITH SIMPLE SNORING AND OBSTRUCTIVE SLEEP-APNEA

Snoring, a symptom which may indicate the presence of the obstructive sleep apnoea syndrome (OSA), is also common in the general population. Recent studies have suggested that the acoustic characteristics of sn oring sound may differ between simple snorers and OSA patients, We hav e studied a small number of patients with simple snoring and OSA, anal ysing the acoustic characteristics of the snoring sound. Seventeen mal e patients, 10 with OSA (apnoea/hypopnoea index (AHI) 26.2 events . h( -1)) and seven simple snorers (AHI 3.8 events . h(-1)), were studied. Full night polysomnography was performed and the snoring sound power s pectrum was analysed. Spectral analysis of snoring sound showed the ex istence of two different patterns, The first pattern was characterized by the presence of a fundamental frequency and several harmonics, The second pattern was characterized by a low frequency peak with the sou nd energy scattered on a narrower band of frequencies, but without cle arly identified harmonics, The seven simple snorers and two of the 10 patients with OSA (AIH 13 and 14 events . h(-1), respectively) showed the first pattern, The rest of the OSA patients showed the second patt ern, The peak frequency of snoring was significantly lower in OSA pati ents, with all but one OSA patient and only one simple snorer showing a peak frequency below 150 Hz. A significant negative correlation was found between AHI and peak and mean frequencies of the snoring power s pectrum (p<0.0016 and p<0.0089, respectively). In conclusion, this stu dy demonstrates significant differences in the sound power spectrum of snoring sound between subjects with simple snoring and obstructive sl eep apnoea patients.