Digital signal analysis of snoring sounds in children.

Snoring sounds of 5 children with sleep-dependent compromised breathing were recorded. Underlying diseases were large adenoids, adeno-tonsillar hyperplasia, hemangioma of the tongue-base and Rubinstein-Taybi's syndrome associated with micrognathia. For comparison snoring sounds of a 42-year-old chronic snorer were analyzed. Time series of the power spectral density of the breath sounds were calculated as well as the mean power spectra of the recordings. The results show that the frequency spectrum reflects the pathomechanism responsible for the production of the abnormal breath sound. In adults, simple snoring is due in large part to vibrations of the soft palate. This can be identified in the frequency spectrum as a low-frequency component with a large number of harmonics. In children with enlarged adenoids and tonsils the soft palate is impeded in its movement which can be demonstrated in the frequency spectrum as a lack of low-frequency components and harmonics. Craniofacial anomalies are characterized by special spectral patterns.