Some hearing aids wearers to have no difficulty using a phone while others may experience whistling or decreased sound. The whistling sound is the feedback that occurs due to sound leakage from around the hearing aid being pushed back into the microphone causing an overload to the system. This can happen when the microphone is covered by a phone. Know where the microphone is on the hearing aid. The microphone of the hearing aid collects the sound to be processed by the circuit inside the hearing aid.
For behind-the-ear models, the microphone is on top of the hearing aid. The phone must be held higher than normal so the sound from the phone is aimed towards the microphone. For in-the-ear models, the phone should be held in front of it. Turning the phone so the back is facing forward and the side is against your head will direct the sound into the microphone without covering it, reducing or eliminating feedback.
