Crackling from a hearing aid usually traces back to moisture trapped inside the device, though earwax buildup, a poor fit, electromagnetic interference, and even your own ear anatomy can produce the same annoying sound. The good news is that most causes are fixable at home or with a quick visit to your audiologist. The trickier part is figuring out which cause you’re dealing with, because the crackling itself sounds similar regardless of what’s behind it.
Moisture Is the Most Common Culprit
Hearing aids live in one of the harshest environments you could design for a piece of electronics: a warm, humid ear canal that produces sweat and oil all day. Even in moderate climates, condensation can form inside the tubing, microphone port, or receiver. In hot or tropical conditions the problem accelerates, because higher temperatures drive more perspiration and push humidity levels inside the device to the point where internal components begin to corrode.
Research on hearing aid failures in tropical regions found that human sweat and electrolyte leakage from zinc-air batteries were the leading causes of corrosion in hearing aid components, with failure rates climbing during summer months as perspiration increased.1Engineering Failure Analysis. Statistical analysis of corrosion failures in hearing aid devices from tropical regions Corrosion doesn’t always kill the device outright. In its early stages it disrupts electrical contacts just enough to produce intermittent crackling, static, or sudden volume drops before the aid fails completely.
Even a tiny amount of moisture can have an outsized effect on sound quality. Field testing with artificial perspiration showed that a dose as small as three microliters caused a 50-decibel decline in acoustic output, and function returned to normal only after professional drying.2The Hearing Journal. Moisture in Hearing Instruments: Problematic, Prevalent, and Professionally Preventable Three microliters is barely a visible droplet. That’s why crackling can appear on a day you weren’t exercising or even visibly sweating. Simple condensation from stepping between air-conditioned indoors and warm outdoor air is enough.
Earwax and Debris Blocking the Receiver
Your ear canal constantly produces cerumen (earwax), and bits of it inevitably migrate into the receiver opening or sound bore of the hearing aid. A partial blockage doesn’t silence the aid the way a full plug does. Instead it creates a narrow, uneven path for sound to travel through, which your ear perceives as crackling, distortion, or a “fuzzy” quality layered on top of speech.
Behind-the-ear models with thin tubing are particularly prone to wax accumulation at the dome or earmold tip, where the tube narrows. In-the-ear models sit deeper in the canal and collect wax directly on the faceplate and receiver port. Either way, a quick visual check with a magnifying glass often reveals a yellowish or brown buildup. Most hearing aids ship with a small cleaning brush and wax pick for exactly this reason. Cleaning the wax guard or replacing the wax filter, if your model uses one, is the single easiest fix you can try before anything else.
A Loose or Poorly Fitting Earmold
When the earmold or dome doesn’t seal snugly against the walls of your ear canal, amplified sound leaks out and gets picked back up by the microphone. The classic version of this is feedback, a high-pitched whistle. But a marginal fit, one that shifts slightly when you chew, talk, or move your jaw, can produce intermittent crackling or popping instead of a sustained whistle. The sound is the feedback loop flickering on and off too quickly to sustain a tone.
Fit changes over time. Weight loss, changes in jaw alignment, or simply the gradual reshaping of cartilage in the ear canal can loosen a mold that fit perfectly a year ago. If your crackling shows up mainly when you’re eating or talking, a fit issue is worth investigating. Your audiologist can refit the mold, switch dome sizes, or apply a venting adjustment to solve the problem.
Electromagnetic Interference From Phones and Other Devices
If the crackling appears only when you’re near your phone, a computer monitor, or certain appliances, electromagnetic interference (EMI) is the likely explanation. Digital wireless phones are a well-documented source: testing of both in-the-ear and behind-the-ear hearing aids found audible interference in the form of buzzing and static at various distances from multiple types of digital wireless telephones.3PubMed. Hearing aid electromagnetic interference from digital wireless telephones The interference comes from the phone’s radio-frequency emissions being picked up by the hearing aid’s circuitry and converted into an audible signal that shouldn’t be there.
Modern hearing aids are generally better shielded than older models, and phones now carry an M-rating (microphone mode) and T-rating (telecoil mode) that indicate how much interference they produce. An M3 or M4 phone paired with an M3 or M4 hearing aid typically produces little to no noticeable interference. But cheap Bluetooth accessories, LED dimmers, some fluorescent lighting, and older microwaves can still cause problems. If you notice the crackling only in specific rooms or near specific devices, try moving away and see if it stops. That’s the quickest diagnostic test for EMI.
When the Crackling Is Actually Coming From Your Ear
Sometimes the crackling you’re hearing isn’t generated by the hearing aid at all. It’s generated by your own middle ear, and the hearing aid is simply amplifying it to a level you can now notice. Eustachian tube dysfunction is one of the most common causes of crackling or popping sensations in the ear. The eustachian tube connects your middle ear to the back of your throat and is responsible for equalizing pressure. When it doesn’t open and close properly, symptoms can include a sense of fullness, pressure, a “clogged” or “underwater” feeling, and crackling sounds, especially during swallowing or jaw movement.4PubMed Central. Eustachian tube dysfunction: consensus statement on definition, types, clinical presentation and diagnosis
The key clue here is timing. If the crackling happens even with the hearing aid out of your ear, or if you notice it only when swallowing, yawning, or changing altitude, the hearing aid is an innocent bystander. Allergies, sinus congestion, colds, and even acid reflux can irritate the eustachian tube and trigger these symptoms. A visit to an ENT specialist rather than your audiologist is the right move in that case. Treating the underlying congestion or inflammation usually resolves the sound.
Temporomandibular joint (TMJ) issues are another overlooked source. The jaw joint sits very close to the ear canal. If the joint pops or clicks, the hearing aid’s microphone can pick up the vibration and amplify it, making a subtle mechanical click sound like an electronic crackle. People who clench or grind their teeth are more susceptible.
Internal Component Wear and Amplifier Distortion
Hearing aids contain miniature amplifiers, digital signal processors, and receivers, all packed into a space smaller than a fingertip. Over time, solder joints can develop micro-fractures, receiver diaphragms can stiffen, and amplifier circuits can degrade. These internal wear issues tend to produce crackling that comes and goes, sometimes triggered by a light tap on the device or by temperature changes that cause components to expand and contract slightly.
Amplifier distortion is a related issue. Every amplifier has a maximum output level. When incoming sound is loud enough to push the amplifier past that ceiling, the output waveform gets “clipped,” producing a harsh, crackly quality on loud sounds. Research into the causes of distortion and internal noise in hearing aids has identified peak clipping and amplifier saturation as key sources of degraded sound quality.5PubMed Central. The causes and effects of distortion and internal noise in hearing AIDS If crackling seems to appear only in loud environments like restaurants or concerts, the amplifier may be hitting its limits. Your audiologist can adjust the maximum power output or compression settings to reduce clipping without losing too much volume.
Battery-related crackling is worth mentioning separately. A zinc-air battery that’s running low delivers inconsistent voltage, which the hearing aid’s electronics interpret as noise. If you use disposable batteries, try a fresh one before troubleshooting further. Rechargeable hearing aids can develop similar symptoms when the lithium-ion cell ages and can no longer hold a stable charge through the day.
How to Troubleshoot Crackling at Home
Before scheduling an appointment, a few minutes of systematic testing can narrow down the cause or fix it entirely.
- Clean the wax guard: Use the brush and pick that came with your hearing aid. If the wax guard is a replaceable filter, swap it for a fresh one. This alone fixes a surprising number of crackling complaints.
- Inspect the tubing: Hold the tubing up to the light. If you see moisture droplets inside, disconnect the tubing from the earmold and blow gently through it, or use the thin cleaning wire supplied with the device. For receiver-in-canal models, check the thin wire and receiver housing for visible moisture or wax.
- Dry the device overnight: Place the hearing aid in a drying jar with desiccant beads or in an electronic drying box with the battery door open (or the rechargeable battery compartment ajar). Even one overnight cycle can resolve moisture-related crackling.
- Swap the battery: A dying battery is one of the simplest explanations. Replace it and see if the crackling stops.
- Check the fit: Reinsert the earmold or dome carefully, making sure it seats fully. If you notice the crackling changes when you press on the mold or wiggle it, the fit has likely loosened.
- Move away from electronics: If the crackling vanishes when you walk into a different room, electromagnetic interference is the likely cause.
- Remove the hearing aid and listen: If you still hear crackling or popping in the affected ear with the device out, the issue is medical rather than mechanical.
Working through that list in order takes only a few minutes and covers the majority of everyday crackling causes. If none of the steps help, it’s time for professional attention.
Professional Drying and Its Impact
Audiologist offices increasingly use professional-grade drying systems that go well beyond what a home desiccant jar can do. These units use controlled heat, vacuum, or ultraviolet light to pull moisture out of internal components that a home kit can’t reach. Field data from hearing care professionals using one such system showed that roughly half of hearing aids brought in as completely “dead” improved enough to function again after drying, while about four out of five aids that were merely weak or underperforming returned to normal output.2The Hearing Journal. Moisture in Hearing Instruments: Problematic, Prevalent, and Professionally Preventable
The practical takeaway is that even if your hearing aid seems to be dying rather than just crackling, a professional drying session is worth trying before paying for a repair or replacement. Many clinics offer this as a routine part of a maintenance visit. If you live in a humid climate, exercising with your hearing aids in, or simply perspire heavily, scheduling a professional drying every few months can prevent crackling from developing in the first place.
Humidity, Lifestyle, and Long-Term Prevention
People who live in tropical or subtropical regions face a disproportionate share of hearing aid moisture problems. The combination of high ambient humidity, higher body temperature, and increased sweating creates conditions where corrosion can accelerate season by season. Research found that corrosion failure rates in hearing aids climbed specifically during summer months in these regions, driven by the dual assault of sweat and battery electrolyte leakage.1Engineering Failure Analysis. Statistical analysis of corrosion failures in hearing aid devices from tropical regions
Lifestyle choices also matter. If you wear hearing aids during vigorous exercise, exposure to steam in a bathroom, or while cooking over a hot stove, you’re bathing the electronics in warm moisture. A sweatband or hearing aid sleeve can help during workouts. Taking the aids out before a shower seems obvious, but the residual humidity in a steamy bathroom after a shower is enough to cause problems if you put the aids back in immediately. Letting your ears and the bathroom air dry for a few minutes first makes a difference.
For rechargeable hearing aids, the charging case itself can trap moisture if the aids go in wet. Wiping them down with a dry cloth before placing them on the charger, and leaving the case slightly open in humid conditions, helps prevent condensation from building up overnight. Some manufacturers now build moisture-resistant nano-coatings into the circuitry, which slows but does not eliminate the problem. No hearing aid is truly waterproof in the sense that a dive watch is. Water resistance ratings like IP68 indicate the device can survive brief submersion, not that it’s immune to the slow accumulation of vapor over weeks and months.
When Crackling Means Something Needs Medical Attention
The ear canal is lined with skin, and skin can develop conditions that affect hearing aid fit and comfort. Eczema or psoriasis in the ear canal can cause flaking skin to accumulate around the earmold, altering the acoustic seal and introducing crackling. A fungal infection of the ear canal, known as otomycosis, produces discharge that can clog the receiver port and corrode contacts. Both conditions cause itching and discomfort alongside the sound changes, which helps distinguish them from purely mechanical issues.
Chronic ear infections or perforated eardrums also change the acoustic environment in ways that a hearing aid’s microphone and processor interpret strangely. If crackling is accompanied by pain, drainage, a sudden change in hearing, or dizziness, skip the audiologist and go straight to a physician or ENT. The hearing aid may need reprogramming after the medical issue is resolved, because the acoustic properties of the ear canal will have changed during the illness.
Older adults sometimes develop exostoses, bony growths in the ear canal often associated with years of cold water exposure. These narrowings can press against an earmold or dome, creating intermittent contact that the aid picks up as crackling. A scan of the canal can reveal whether the fit is being physically compromised, and a custom earmold shaped to accommodate the growth usually resolves the issue.