the sounds heard through the stethoscope when the patient speaks (“ninety nine”). These are normally just audible but become much louder (bronchophony) if the lung under the stethoscope is consolidated, when they resemble the sounds heard over the trachea and main bronchi. Vocal resonance is lost over pleural fluid except at its upper surface, when it has a bleating quality and is called aegophony. See also pectoriloquy.... vocal resonance
Health Encyclopedia