1. Intensity of inspiration and expiration is quieter at the bases than the apex. a. Vesicular (normal breath sound): a soft rustling sound heard throughout all of inspiration and the beginning of expiration. b. Bronchial: a more hollow, echoing sound normally found only over the right superior anterior thorax. This corresponds to an area over the right main stem bronchus. All of inspiration and most of expiration are heard with bronchial breath sounds. c. Bronchovesicular: intermediate breath sound between bronchial and vesicular with equal periods of inspiration and expiration. d. Decreased: a very distant sound not normally heard over a healthy thorax; allows only some of the inspiration to be heard. Often associated with obstructive lung diseases.
2. Adventitious (extra) sounds. According to the American Thoracic Society, there are only two adventitious breath sounds a. Crackles (also termed rales, crepitations): a crackling sound heard usually during inspiration that indicates pathology (atelectasis, fibrosis, pulmonary edema). b. Wheezes: a musically pitched sound, usually heard during expiration, caused by airway obstruction (asthma, chronic obstructive pulmonary disease [COPD], foreign body aspiration). With severe airway constriction, as with croup, wheezes may be heard on inspiration as well.
3. Vocal sounds. a. Normal transmission of vocal sounds. • As with breath sounds, vocal transmission is loudest near trachea and main-stem bronchi. • Words should be intelligible, though softer and less clear at the more distal areas of the lungs. b. Abnormal transmission of vocal sounds may be heard through fluid-filled areas of consolidation, cavitation lesions, or pleural effusions. • Egophony is a nasal or bleating sound heard during auscultation. “E” sounds are transmitted to sound like “A.” •Bronchophony, characterized by an intense, clear sound during auscultation, even at the lung bases. • Whispered pectoriloquy occurs when whispered sounds are heard clearly during auscultation. |