Use of a contact microphone for high-quality recording of snoring during natural or drug-induced sleep

Background: Selected adult patients with obstructive sleep apnoea-hypopnea syndrome (OSAHS) may benefit from surgical intervention. At present, the dominant technique for the diagnosis of the anatomical locus of upper airway obstruction during sleep is drug-induced sedation endoscopy (DISE). This technique is widespread, but has generated controversy related to its artificiality. Methodology: We present a technique for the acquisition of high-quality and consistent recordings of snoring sounds, suitable for advanced acoustic analysis and correlation with the findings of DISE. Results: Analysis of the generated recordings demonstrates distinct frequency-domain characteristics of snoring sounds generated by distinct anatomical subsites, for example the soft palate, or tongue base. Conclusions: Supplemental information may potentially be obtained from the waveform of snoring sounds produced by the patient; however, no robust quantitative “assay” has been developed or been clinically validated. This may in part be related to inconsistencies or insufficient quality of the sound data acquired. This novel technique may circumvent these difficulties and permit more advanced analysis techniques with potential clinical applicability.