Wax build-up is the most common cause for “weak” or “dead” custom instruments being returned to ReSound for repair.
To illustrate the impact of a plugged wax filter, response curve Hearing Instrument Test (HIT) measures were obtained for a hearing instrument in two different scenarios. It was run once with a plugged wax filter and then run with a new /clean wax filter. You can see the “diminished” acoustical response, especially in the high frequencies, as compared to the same instrument with a new wax filter.
If regular maintenance is not performed, wax can migrate past the filter and cause permanent damage to the electronics. We recommend counseling patients to change their wax filter regularly to ensure the sound quality of the hearing instrument is optimized and damage to the hearing aid components is prevented.