What indicates a significant difference in hearing ability between air conduction and bone conduction testing, where bone conduction is better?

The concept of air-bone gap is essential in audiology, particularly when interpreting the results of air conduction and bone conduction hearing tests. A significant difference in hearing ability between these two testing methods indicates the presence of a gap, which suggests a specific type of hearing loss.

When bone conduction thresholds are better than air conduction thresholds, it often signals conductive hearing loss, where sound is impeded in the outer or middle ear, affecting how sound travels through the air. Bone conduction, on the other hand, bypasses these structures, directly stimulating the cochlea and providing a clearer measure of the inner ear's function.

An air-bone gap is defined as the difference in the thresholds of these two types of conduction. It is typically measured in decibels (dB) and indicates that although the inner ear may function normally (bone conduction is good), the outer or middle ear system is not conducting sound efficiently (air conduction is poorer). This gap can help audiologists make critical decisions about the type of hearing loss present and potential treatment options, such as medical or surgical interventions for conductive loss, or the fitting of hearing aids if there's associated sensorineural loss as well.

Understanding the implications of an air-bone gap is crucial for diagnosing hearing issues