What does insertion gain measure in hearing aids?

Insertion gain specifically refers to the measure of sound pressure level gain at the eardrum when a hearing aid is worn by the user. This value is determined by using a probe microphone that captures the sound levels at the eardrum while the hearing aid is in place. It assesses how much amplification the hearing aid provides in real-world settings, thereby reflecting how effectively the device improves the user's hearing in their specific ear canal configuration.

This measurement is crucial because it gives audiologists and dispensers information about how well the hearing aid is performing in situ as it accounts for the unique acoustics of the individual's ear. By assessing the gain at the eardrum, professionals can tailor the hearing aid settings to ensure optimal amplification that suits the user's hearing loss profile, enhancing the overall effectiveness of the device.

Thus, insertion gain is a critical factor in evaluating and adjusting hearing aids for personal auditory needs.