Breath sounds are the sounds made by air as it moves through the respiratory system. Breath sounds are also called lung sounds or respiratory sounds. Sometimes they can be heard by anyone; other times they can be heard only by listening to the lungs and airways with a stethoscope.

To describe and identify breath sounds, medical professionals usually use auscultation (they listen with a stethoscope). They listen while the patient is breathing in, and while they are breathing out. They listen to both lungs, at both the chest and the back, starting at the bottom and working their way up. They listen to whether the pitch of the breath sounds is low, medium or high. They also listen to whether the sounds are soft, medium, loud, or very loud).