Snoring: A rough rattling noise made on inspiration during sleep by vibration of the soft palate (the back of the roof of the mouth) and the uvula (the prominent structure dangling down at the back of the mouth).

On inspiration, air on its way to the lungs travels by the tongue, the soft palate, the uvula, and the tonsils. When a person is awake, the muscles in the back of the throat tighten to hold these structures in place and prevent them from collapsing and vibrating in the airway. During sleep, the soft palate and uvula may vibrate causing the sounds of snoring. Snoring is believed to occur in anywhere from 30% of women to over 40% of men.