Normal Breath Sounds

Normal breath sounds are characterized by a low noise heard during inspiration. During expiration these noises are hardly audible.1 The sound is not musical, and there are no discrete peaks.4 The inspiratory component of the sound is mostly generated within the lobar and segmental airways while the expiratory component is produced from more proximal areas.4 Air turbulence is thought to generate normal lung sounds.4

Listen to the examples of normal breath sounds.

Note: recordings were made with a 3M Littmann Electronic Stethoscope 3200 in a clinic setting with patients at rest.