What is an air-bone gap?

An air-bone gap refers to the difference in hearing sensitivity measured through air conduction compared to bone conduction thresholds. When there is a 15 dB or greater difference between these thresholds in the same ear, it indicates that the air conduction is significantly poorer than bone conduction. This condition suggests that there is likely a conductive hearing loss occurring, as the bone conduction, which bypasses the outer and middle ear, is better than the air conduction, which involves those structures.

This definition is critical in audiology as it helps differentiate between types of hearing loss: conductive and sensorineural. In cases of conductive hearing loss, sound is not being effectively transmitted through the outer or middle ear, leading to poorer air conduction results. Conversely, bone conduction remains intact, indicating that the inner ear and auditory nerve are functioning correctly.

Understanding this concept is essential for hearing aid specialists, as it assists in evaluating the cause of hearing loss and determining the appropriate interventions or treatments for the patient.