Bronchophony · What Is It, Causes, and More

Bronchophony is a type of pectoriloquy, which is when voice transmission through lung structures is heard with a higher resonance. In particular, bronchophony refers to an atypical increase in the intensity and clarity of the individual’s spoken voice heard when auscultating the lungs with a stethoscope. The presence of bronchophony indicates consolidation of the lung tissues and may suggest the presence of an underlying condition. 

Testing for bronchophony involves asking the individual to repeat a certain word or phrase, such as ‘ninety nine’ or ‘scooby doo,’ while auscultating the individual’s lungs at different locations. Typically, healthy lung tissue is filled with air, leading to a muffled sound transmission. However, some disorders may cause lung tissues to consolidate, or become fluid-filled and airless, leading to an enhanced sound transmission. This is because sound is conducted better through liquid or solid, as opposed to air, which causes a disruption in sound transmission. As a result, in areas of consolidation, the sound of spoken words is heard louder and clearer in comparison to healthy lung tissue, resulting in bronchophony. 

Egophony and whispered pectoriloquy are other types of pectoriloquy, which consist of slightly different testing techniques, yet with similar clinical significance. In whispered pectoriloquy, the individual is asked to whisper the words, rather than repeating them out loud. In this case, sounds appear to be faint or hardly audible in an air-filled lung, but heard louder and clearer over areas of lung consolidation. Similarly, in egophony, there is an increased resonance of vowel sounds, which appear to be distorted in areas of consolidation. For example, a spoken ‘ee’ sound may be heard as ‘ah’ or ‘ay’.

Generally, bronchophony is caused by an area of increased lung density, or consolidation. This may be due to fluid entering the lung tissues, like in pneumonia; the partial or total collapse of a lung, known as atelectasis; or the presence of a solid mass in the lungs, such as a tumor.