Abstract: A system and method to diagnose a medical condition using sound recordings. Included is a method to diagnose sleep apnea by computing a sleep index based on an analysis of snoring of the patient. This can be accomplished via a recording of the patient sleep sounds using sensors (e.g., microphones) available in a smart mobile device. A sleep index is calculated that is highly correlated to the Apnea-Hypopnea Index and can be used as an objective diagnosis indicator for sleep apnea.