Q: Lately my hearing aids keep cutting in and out, why is that happening, and is there something I can do to stop it?
A: This is a question we’ve been getting a lot lately, and it is a common question during summer months, or if people live where it’s hot and/or humid. There are several things that can make a hearing aid become intermittent, but in 90% of the cases we see at our clinics, the major cause is moisture, and the culprit is hot and humid weather.
Last week the temperatures in southern Ontario soared and humidity levels were very high. People with breathing problems were having a tough time as the pollution index increases with this oppressive humidity, and so were people who were active while wearing their hearing aids.
Humidity is something Hearing Specialists are used to; the fact is that the human ear canal is a harsh environment. The temperature of the canal at the level of the Tympanic Membrane, (the ear drum), is close to normal body temperature of 37o Celsius, (98.6o Fahrenheit), and the production of cerumen, (ear wax), adds moisture to the system. This is quite intentional; in a normally functioning ear the wax is there to perform two functions: The first is to keep the skin in the ear canal moisturized. The cerumen consists of many different compounds, but mostly it is keratin and cholesterol based sebaceous fluid, and a little bit of dead skin. These oily substances keep the ear canal lubricated and also protect it from several bacteria, insects, fungi and water. The second is to remove any dust or airborne particles from the ear canal. So it is a very important bi-product of our auditory biology.
Problems arise when wax collects in the canals. There are several reasons this can happen, the most common is the use of cotton swabs, which, in spite of what you may think, tend to push wax back into the ear canal, (normally the skin beneath the wax, the epithelium, migrates out toward the outer ear and the wax dries and flakes off harmlessly into our air filters), where it accumulates and eventually impacts. Sometimes our ears overproduce wax; the sebaceous glands lose their ability to moderate their production and we make too much of it. But in a few cases the very hearing aids we use to hear with could be the reason wax collects. The use of some styles of instrument will do the same as a cotton swab; push the wax back in onto itself and impact it. This is why going coming to see us regularly is important. It’s one of the many things we check when you come in, even for just a cleaning.
All the while, the hearing aid is being exposed to this moisture and heat and often that moisture is collected in the tubing that supports the receiver, (speaker), of the hearing aid. If it gets too much moisture the receiver gets blocked and the hearing aid no longer produces the sounds it’s supposed to produce. The problem with this is that it is very hard to see; it oily water, (sweat and wax), and may not be as obvious as most people think. When it’s just wax we can see it and clean it out. Moisture is almost invisible to us in such a small dark space and many people then think it’s something inside the hearing aid circuitry.
This is not all that farfetched; I have seen cases where moisture buildup was so much that it corroded the circuitry inside the hearing aid, but this is incredibly rare, particularly now that most manufacturers are putting something called “nanocoating” on most of their circuits. The nano coating is a very thin coating, (10-9 meters), that gets onto the surface of the entire circuit and seals it from moisture, acting as a strong barrier from water and other liquids. Hearing aids that claim to be “waterproof” or “water resistant” have this coating, but the demand for it has since dropped the price of the commodity and they generally use it on most of their products, because it cuts down on these problems and therefore repair costs while the hearing aid is under warranty.
In 90% of the cases we can get the hearing aid up and working again with a quick visit to the office, and that’s mostly thanks to the new technologies afforded to us by the research done in the name of better hearing.