Lung sounds also known as breathing or respiratory sounds are the noises identified through auscultation in the structures of the lungs.
Normal breath sounds are classified as tracheal, bronchial, bronchovesicular, and vesicular sounds.
Decreased, absent breath sounds and "adventitious sounds" are considered abnormal breath sounds.
The picture below used for mnemonics for nursing shows some of the different adventitious lung sounds and their respective area of auscultation.