Hearing Aid Feedback and Whistling: Why It Happens and How to Fix It

If you've ever heard a high-pitched squeal or whistle coming from your hearing aid — or noticed people around you reacting to a sound you can barely hear — you've experienced acoustic feedback.

It's one of the most common complaints among new hearing aid users. The good news: in most cases, it's fixable in minutes.

What Is Hearing Aid Feedback?

Acoustic feedback occurs when amplified sound leaks out of your ear canal and gets picked up again by the hearing aid's microphone — creating a loop that produces a whistling or squealing sound.

Think of it like a microphone held too close to a speaker at a concert. The same physics apply at a much smaller scale inside your ear.

Why Does It Happen?

1. Poor fit or improper insertion
The most common cause. If the hearing aid isn't seated correctly in the ear canal, amplified sound escapes around the edges and re-enters the microphone. This is especially common with CIC devices during the first few weeks of use.

2. Volume set too high
Higher amplification means more sound to potentially leak. If feedback only occurs at maximum volume, the device may be amplifying beyond what your ear canal can contain.

3. Earwax buildup
A blocked ear canal changes the acoustic environment. Wax can redirect sound back toward the microphone instead of allowing it to be absorbed naturally.

4. Jaw movement
Chewing, yawning, or talking changes the shape of your ear canal slightly. For some users, this temporary change creates a gap that allows sound to escape — causing feedback only during eating or conversation.

5. Hand or object near the ear
Cupping your hand over your ear, hugging someone, or holding a phone close to your ear can reflect amplified sound back into the microphone. This is normal and not a sign of malfunction.

6. Damaged or worn eartip/dome (BTE users)
A cracked or misshapen dome no longer seals the canal properly, allowing sound to escape consistently.

How to Fix Hearing Aid Feedback

Step 1: Reinsert the device
Remove and reinsert your hearing aid carefully, ensuring it's fully seated. For CIC devices like the RKEPIE M602, the device should sit snugly in the canal with no gaps around the shell.

Step 2: Check for earwax
If feedback is persistent, check the sound outlet for wax buildup and clean it with the included brush and wax pick. A blocked outlet is a common hidden cause.

Step 3: Reduce volume slightly
If feedback only occurs at high volume settings, try reducing amplification by one level. If you need that volume to hear clearly, the issue may be fit-related rather than volume-related.

Step 4: Replace the dome (BTE users)
For RKEPIE M802 BTE users, remove the dome and inspect it for cracks, deformation, or discoloration. A worn dome should be replaced — they're inexpensive and widely available.

Step 5: Try a different dome size
If feedback persists after replacing the dome, the size may not be right for your ear canal. A slightly larger dome creates a better seal and reduces sound leakage.

When Is Feedback Normal?

Some feedback situations are completely normal and not a sign of malfunction:

• When inserting or removing the device (brief squeal as it passes through the canal)
• When cupping your hand directly over your ear
• When someone hugs you and their head comes close to your ear
• During the first 1–2 weeks of use while you're learning proper insertion technique

When Should You Be Concerned?

Persistent feedback that doesn't resolve with reinsertion, cleaning, or dome replacement may indicate:

• The device shell or dome size doesn't match your ear anatomy
• Internal microphone damage (rare, usually from drops or moisture)
• Significant earwax impaction requiring professional removal

If feedback continues after trying all the steps above, contact the manufacturer or consult a hearing professional.

CIC vs BTE: Which Has Less Feedback?

Both styles are designed to minimize feedback when properly fitted. The M602 CIC's deep canal placement naturally reduces feedback risk. The M802 BTE comes with multiple dome sizes to ensure a proper seal.

The Bottom Line

Hearing aid feedback is almost always a fit or maintenance issue — not a defect. Reinsertion, cleaning, and dome replacement resolve the majority of cases within minutes.

If you're a new user experiencing occasional feedback, give yourself 2–3 weeks to master the insertion technique. Consistent, proper fit is a skill that develops quickly with practice.

Experiencing persistent feedback with your RKEPIE hearing aid? Contact our support team at rkepie.com — we'll help you find the right fit.