ABSTRACT
Respiratory sounds are generated by airway wall vibration during breathing. Vibrating airways produce pressure waves that travel through the body and along conducting airways and may be heard at the nostril opening or by auscultation if they are in the audible range (20-20,000 Hz). Abnormal respiratory sounds are superimposed on normal sounds and reflect a change in the relationship between flow rate through the airways, their size, and wall compliance.
