If your hearing aids whistle when you hug someone, take off a mask, or turn your head just so—welcome to the club. Feedback is common, fixable, and a fascinating mix of physics and clever signal processing. The good news: today’s tech is excellent at squashing it. The better news: a few tweaks to fit and habits can make your hearing both clearer and quieter.

Let’s demystify what causes that squeal, how your devices fight back, and the steps that get you more volume without the shriek.

What Exactly Is Hearing Aid Feedback?

Feedback happens when sound from the hearing aid’s speaker (receiver) leaks out of your ear and gets picked up again by the microphones. That creates a loop—like standing too close to a PA system—amplifying a narrow pitch until it whistles.

Common real-life triggers

  • Loose fit or shallow insertion: The dome or earmold isn’t sealed well, so amplified sound escapes.
  • Vents and open domes: Great for a natural voice, but easier for sound to leak back to the mics.
  • Earwax or moisture: Blocks sound going into the ear, so more sound bounces back out.
  • Hands, hats, hair, masks, or glasses: Reflect sound toward the microphones.
  • Jaw movement: Chewing or smiling can momentarily break the seal and let sound leak.

None of this means your hearing aids are bad. It means physics is persistent—and your devices are trying to outsmart it.

The Tech Inside: How Feedback Cancellation Works

Modern hearing aids use several strategies to raise the “gain before feedback”—how much amplification you can enjoy before the whistle starts.

1) Adaptive feedback cancellation (AFC)

Your hearing aids continuously estimate the path that leaked sound takes from the receiver back to the microphones. They generate an equal-and-opposite signal to cancel that leakage (think noise-canceling headphones, but for the feedback path). Because your ear and environment change second by second, the algorithm adapts in real time.

2) Notch filters and phase tricks

When a single pitch starts to squeal, the processor can drop a selective “notch” at that exact frequency or shift the phase so the loop can’t build. You keep most of your amplification, but the squealiest frequency is de-emphasized.

3) Feedback calibration

Many fittings include a quick “feedback test.” The hearing aid plays a controlled sound and measures how close you are to feedback across frequencies. The software then shapes your gain and safety margins so you can use more volume comfortably.

4) Smarter detection to avoid “entrainment”

Older systems could mistake pure tones in music or alarms for feedback and add warbly, underwater artifacts. Newer strategies analyze timing and spectral patterns to distinguish your favorite violin note from an actual feedback loop—so music stays music.

Important: even great algorithms can be outmatched by a very leaky fit or blocked ear canal. That’s where simple physical fixes make a big difference.

Fit and Physics: Your Role in Silence

Before you dive into app settings, check the basics. Small changes can buy you a big chunk of feedback-free volume.

  • Insert fully and consistently: A dome sitting 2–3 mm too shallow can whistle. Gently twist as you insert until it’s snug and comfortable.
  • Choose the right dome or mold: Double-flange or “power” domes seal better than open domes. Custom earmolds, especially with deeper canals, reduce leakage further.
  • Mind the vent: Larger vents feel more natural but leak more sound. If feedback is chronic, ask about a smaller or pressure-vented option.
  • Keep paths clear: Change wax guards and domes on schedule. A blocked receiver pushes sound backward, not forward.
  • Check tubing, receivers, and retention: Cracked tubes, loose receivers, or missing retention tails let mics and speakers get too cozy.
  • Glasses and masks: Seat the hearing aid first, then put on glasses. For masks, choose thin ear loops or mask clips to avoid pushing the aid’s mic port.

If you’re unsure about insertion depth, dome type, or maintenance, a quick visit with an audiologist can solve it faster than trial-and-error.

When a Squeal Means “Call Your Provider”

Feedback is common, but certain changes are a nudge to get help:

  • New feedback that wasn’t there: Could be earwax, a device issue, or a fit change after weight loss.
  • Persistent whistle at typical volumes: You might need a different dome/mold, receiver power, or a refit with feedback recalibration.
  • Discomfort or soreness: Don’t force a seal that hurts. A custom mold or deeper, contoured fit can improve comfort and feedback.

An audiologist can inspect your ears, check the devices, run real-ear measurements, and recalibrate feedback controls to restore quiet gain. If you have pain, drainage, sudden hearing changes, or dizziness, seek medical evaluation with an ENT promptly.

Settings That Matter: The Trade-offs

More openness usually equals more natural sound—but also more leakage risk. A few setting themes to understand:

  • Open vs. closed fit: Open domes reduce occlusion (your voice booming) but invite feedback. Closed domes or custom molds raise the feedback ceiling but may make your voice feel fuller. Your clinician can balance both.
  • High-frequency gain: Feedback often lives up high. Cutting too much treble tames squeal but can blur speech clarity. Better to fix fit and recalibrate than to over-trim audibility.
  • Music programs: Music has long, pure tones. Ask for a music program tuned to avoid unnecessary feedback suppression while preserving fidelity.
  • Streaming and phone position: Holding a phone too close to the mic can trigger feedback. Try shifting the angle slightly or use Bluetooth streaming when possible.

More Gain, Less Whistle: Practical Upgrades

  • Real-ear verification (REM): Verifies and fine-tunes amplification inside your ear canal, often squeezing out a few dB of clean, stable gain. Ask your provider if they use REM.
  • Custom earmolds with deeper canal length: More stable seal, less movement with jaw/chew. Soft silicone molds often seal better in tricky canals.
  • Appropriate receiver power: A too-weak receiver pushed to the limit distorts and invites feedback. The right power class can be quieter at the same loudness.
  • Re-run feedback calibration after changes: Any new dome, mold, tubing, or wax guard swap can shift the feedback path. A quick in-clinic recalibration raises your safety margin.
  • Consider smaller vents or pressure-vent tech: Some systems use clever vent designs to reduce leakage while retaining comfort.
  • Keep a safety margin: Many fittings aim for a few dB below the feedback limit, so everyday movements don’t push you over the edge.

Myth-Busting: Feedback Edition

  • “Only cheap aids whistle.” Any device can feed back if fit and physics line up the wrong way. Premium tech helps a lot, but a leaky fit can outsmart any algorithm.
  • “Just turn it down.” Constantly lowering volume can cost you speech clarity. Fix the cause—fit, wax, recalibration—so you can listen comfortably at the right level.
  • “If it squeals, the mold is wrong.” Not always. Sometimes it’s insertion depth, a blocked wax guard, a cracked tube, or a simple mic reflection from hair or a hat.

The Two-Minute Quiet Checklist

  • Reinsert the hearing aid so the dome/mold sits fully and comfortably.
  • Wipe moisture and brush ports; swap wax guards if near due.
  • Make sure domes are the right size and snapped on fully.
  • Seat glasses first, then the hearing aids, then your mask.
  • Open your app: reduce treble a notch only as a temporary fix.
  • If feedback keeps popping up, schedule a fit check and feedback calibration.

The goal isn’t just to stop the squeal. It’s to give you the stable, crystal-clear gain that makes conversation easy again. If feedback is stealing your volume or confidence, an hour with an audiologist can change your everyday listening in a big way.

Friendly nudge: don’t struggle solo. A hearing care professional can inspect your ears, optimize your devices, and teach insertion tricks that stick.

Further Reading

- Self‑Fitting Hearing Aids, Demystified: How OTC Tech Tunes to Your Ears (and When to Get Help) (Technology) - Music, Not Mush: Tuning Hearing Aids So Songs and Instruments Sound Right (Hearing Aids) - Make Your Voice Sound Natural in Hearing Aids: Beat the Occlusion Effect (Hearing Aids) - OTC Hearing Aids, Done Right: Self‑Fit, Save, and Know When to Get Help (Hearing Aids)

Frequently Asked Questions

Why do my hearing aids whistle only when I hug people or wear a mask?

Hugs, hands, masks, hats, and even hair can reflect amplified sound right back into the microphones, briefly creating a feedback loop. Masks and glasses can also nudge the device or change how the dome seals. A tighter seal, different dome style, or small fit adjustment usually solves it.

Can feedback damage my hearing or the aids?

The squeal is annoying but not harmful at typical levels. The bigger issue is that it limits how much clean gain you can use, which can make speech harder to understand. Fixing the cause lets you listen at the right volume comfortably.

Will switching to custom earmolds eliminate feedback?

Custom molds often reduce feedback by creating a stable, deeper seal, especially for higher prescriptions. They don’t guarantee zero whistle—vent size, insertion depth, wax, and reflections still matter—but they raise the ceiling so you can use more gain without squeal.

My aids used to be quiet. Why the sudden squeal?

Common culprits include a blocked wax guard, cracked tubing, moisture, a loose dome, earwax buildup, or a change in ear shape/weight. Have your ears and devices checked, clean or replace the coupling parts, and re-run feedback calibration.

References