Bronchophony, also known as bronchiloquy, is the abnormal transmission of sounds from the lungs or bronchii. It is a general sign, detected by auscultation. The patient is requested to repeat a word several times (the numbers "ninety-nine" or "sixty-six" are traditional) while the physician auscultes symmetrical areas of each lung. Normally, the sound of the patient's voice becomes less distinct as the auscultation moves peripherally; bronchophony is the phenomenon of the patient's voice remaining loud at the periphery of the lungs or sounding louder than usual over a distinct area of consolidation (such as pneumonia). This is a valuable tool in physical diagnosis used by medical personnel when auscultating the chest.
Often, the patient does not have to speak for the physician to hear signs of bronchophony. Rather, the normal breath sounds are increased in loudness over the affected area of the lungs (referred to by doctors as "increased breath sounds.")
Bronchophony may be caused by a solidification of lung tissue around the bronchii, which may indicate lung cancer, or by fluid in the alveoli, which may indicate pneumonia. However, it may also have benign causes, such as wide bronchii. As such, it usually an indication for further investigation rather than the main basis of a diagnosis.