A common cause of hearing aid feedback is which of the following?

• A. Earmold is not seated correctly in the canal or tubing cracked or broken
• B. Battery is dead
• C. Wax buildup in canal
• D. Using the wrong battery size

Answer: (A)

Feedback happens when the amplified sound from the hearing aid escapes the ear canal and is picked up again by the microphone, creating a loop that you hear as a whistling or screeching sound. The most common way this occurs is when the earmold isn’t seated correctly in the ear canal or the tubing is cracked or broken. Those gaps let air and sound leak out, and that leakage gets re-amplified, producing feedback.

Other issues won’t produce feedback in the same way: a dead battery stops the device from delivering sound, so there isn’t a loop to feed back. Wax buildup can change how well the seal fits and may contribute to improper seal or occlusion, which can influence feedback indirectly, but it’s not the primary cause. Using the wrong battery size affects power and operation, not the acoustic feedback loop itself.