Squeal no more

19 Apr Squeal no more

Many of us have memories of our grandparent’s hearing aids squealing a head-ache inducing screech. For some people, memories of those “dead give-away” squeals deter them from searching for a solution for their hearing loss. The good news is, today’s digital hearing aids have feedback suppression systems, which minimize that squeal (called feedback).

But first, what is that squeal sound we call feedback? In general, there are three types of feedback:

1. Acoustical Feedback: this is caused when the amplified sound from the hearing aid speaker is picked up again by the aid’s microphone. This creates a sound loop that gets louder and squeals. This is comparable to when a musician takes their microphone too close to the speaker, and you hear a loud screech. This is acoustical feedback, and along with a good fitting hearing aid, feedback management systems work to suppress the occurrence of acoustical feedback.
2. Mechanical Feedback: this occurs when physical vibrations occur because the hearing aid speaker and the hearing aid casing are touching. This is an easy fix.
3. Electronic Feedback: This occurs due to a malfunction in the hearing aid circuitry  and requires servicing by a hearing aid technician.

All types of feedback require the expertise of a hearing health care professional. The most common type of feedback is acoustical feedback, and below are possible troubleshooting tips the hearing health care professional will use:

• Check for earwax: when a sound wave hits a solid block of earwax, that sound wave disperses and sends sound in multiple directions, including back out the ear to get re-amplified by the hearing aid microphone. Wax removal can be arranged with your audiologist or family physician.
• Check the fit: A loose fitting hearing aid allows amplified sound waves to escape the ear canal around the hearing aid, reach the mic and start a feedback loop. For example, If you’ve lost weight, your ear canal shape can change, resulting in a loose fitting hearing aid at risk for feedback
• Check for Hearing Aid Damage or Debris: If the hearing aid is damaged, as in the casing is cracked or other internal damage, or if the hearing aid requires servicing (tubes changed, wax filters changed), this may result in feedback until the appropriate servicing is completed.
• Check the Insertion: if the hearing aid is inserted improperly, this can cause a feedback loop due to sound leakage from the ear canal.
• Make Changes to the Programming: If the above options do not solve the feedback, your audiologist will make adjustments to the feedback suppression system. When the feedback suppression system detects a hint of feedback, it automatically adjusts itself to suppress the feedback. The more advanced the hearing aid, the more advanced the feedback suppression system.

In most cases, feedback should only occur if the hand is cupped over the ear. If you are getting feedback on frequent occasions, contact your hearing health care professional to see how they can help!