Using our stethoscopes, let's learn how to listen to lung and breath sounds during a respiratory exam! Breath sounds are the noises produced by the structures of the lungs during breathing. The lung sounds are best heard with a stethoscope. This is called auscultation. Normal lung sounds occur in all parts of the chest area, including above the collarbones and at the bottom of the rib cage. Absent or decreased sounds can mean: Air or fluid in or around the lungs (such as pneumonia, heart failure