The "Phantom" Sound
That high-pitched squeal isn't broken electronics—it's physics. Acoustic Feedback occurs when amplified sound leaves the speaker (receiver) and finds a way back into the microphone, creating a continuous loop. It's the same effect as a microphone getting too close to a speaker on stage, but happening inside your ear.
How The Loop Happens
Sound leaks out and gets re-amplified. Follow the path below.
Picks up external sound.
Makes the sound louder (Gain).
Sends sound into ear canal.
Ideally, sound stops here.
The red path represents the "Feedback Loop"
Common Culprits
Based on clinical troubleshooting data, feedback is rarely a device failure. It is usually a mechanical or physical issue.
The Cost of Feedback
It's not just annoying; it affects utility. When feedback occurs, the hearing aid's processor often reduces gain (volume) to stop the whistling, significantly reducing speech intelligibility.
- 📉 Reduced Gain: Aids automatically turn down to stop the squeal.
- 🗣️ Poor Speech Clarity: Consonants become muddy.
- 😤 User Fatigue: Brain works harder to fill gaps.
Troubleshooting Protocol
Follow these steps in order before calling your audiologist.
1. The "Hug" Test
Does it only whistle when you hug someone or put a phone to your ear? This is normal feedback due to object proximity reflecting sound back immediately.
Pull device slightly away from objects. If it stops, the aid is likely working fine.
2. Check for Earwax
If the canal is blocked, sound bounces off the wax wall and leaks back out. This is a massive cause of sudden feedback.
Check your ear canal visually and clean the hearing aid wax filter.
3. The Fit Check
Did you lose weight? Is the dome inserted fully? Loose fitting aids allow sound to escape around the edges.
Push the device gently deeper. If whistling stops, the fit was too loose.
4. Mechanical Failure
Cracked tubing or a dislodged internal receiver can cause internal feedback loops.
Inspect plastic tubing for cracks. If found, see your provider immediately.
© 2023 Hearing Health Infographics. Generated for Educational Purposes.
Disclaimer: This guide is for informational purposes only. Always consult a licensed audiologist for medical advice.