Any difference between how a person should hear and how they actually hear if some of the sound is being lost as it passes through the middle ear. In hearing testing, any difference between hearing responses for earphone or loudspeaker (air conduction) and bone vibrator (bone conduction). A gap or difference between air-conduction and bone-conduction responses indicates a conductive hearing loss due to problems in the middle ear.
Home Glossary Terms Air-Bone Gap