International Journal of Pediatric Otorhimdal3'ngologv, 12 (1986) 173-185 173 Elsevier POR 00404 Digital signal processing of stridor and snoring in children Alberto Leiberman, Arnon Cohen and Asher Tal Departments of Otolao,ngologr and Pediatrics, Soroka University Hospital and Faculty of Health Sciences; and Department of Electrical and Computer Engineering Biomedical Engineering Program. Ben-Gurion Uni~,ersiO'. Beer-Sheva (Israel) (Accepted 8 October 1986) Key words: Stridor; Snoring: Digital signal processing; Power spectral density; Estimated cross-sectional area Summary Stridor and snoring are common signs of upper airway obstruction. The nature and characteristics of the stridor and snoring depend upon the site of obstruction. Sophisticated analysis of these sounds may provide important information concern- ing the source of the sound helping to assess the patient more objectively. The preliminary results of computerized digital analysis of stridor and snoring sounds are presented in 5 children. Two main programs were applied to analyse the signal: (1) the Power Spectral Density (PSD) function and (2) the Estimated Cross-sec- tional Area (ECSA). A consistent pattern according to the site of the produced sound was seen. Further acoustical analyses are needed to standardize this method and to program the computer to indicate the various sites of lesions. Introduction Stridor and snoring are common signs of upper airway obstruction (UAO) in children. The clinical importance of these sounds had been recognized long ago, and it is of great clinical value in the diagnosis, treatment and follow-up of patients suffering from UAO [3,5,7]. Stridor is a sign found frequently in children as a result of turbulent airflow through a partial obstruction of the airway. Many factors have been reported to obstruct the airway at different levels. Depending on the site of the Correspondence: A. Leiberman, Department of Otolaryngology,Soroka Medical Center, P.O. Box 151, Beer-Sheva 84010, Israel. 0165-5876/86/$03.50 '~ 1986 Elsevier Science Publishers B.V.