Audioprosthologist Dan Taylor speaks to the negative effects of humidity and moisture on hearing aids, and what can be done to resist these issues

With winter over and the arrival of spring, increasing humidity and afternoon thunderstorms are here once again. Traditionally, this weather also brings an increase in the number of moisture-related hearing-aid issues. With such a miniature electronic device, hearing instruments plus moisture equals problems. These problems can be simple to fix, or go unnoticed and hidden, until internal corrosion progresses beyond the point of possible repair.

“However you cut it, moisture in your hearing aids is not a good thing. Over the years our industry has evolved a wide variety of strategies, some more effective than others,” explains R.D. Dan Taylor, owner of A Advanced Hearing in downtown Melbourne.

Taylor is nationally board certified in hearing instrument sciences, a certificate holder of the American Conference on Audioprosthology as an audioprosthologist and has been licensed by the State of Florida to dispense hearing aids since 1983.

Taylor explains that a few years back a Japanese company invented a waterproof hearing aid as a possible solution to moisture-related issues.

“I saw it at one of our conventions being displayed totally submerged in an aquarium, complete with fish, plastic plants, filter and treasure chest. They’d connected it to a stethoscope so that anyone passing by could listen in on the fish, I guess. Well, I never saw that system outside of an aquarium and on a single patient. The fact that it was the size of a small banana, built like a small plastic submarine and priced like a real one, might have had something to do with them not catching on. But, it remains the only hearing aid I can ever remember being advertized as ‘waterproof,’” he says.

MOISTURE MITIGATION: AN EFFECTIVE LIFE-EXTENDING STRATEGY
Moisture mitigation, as in drying the aids out in between usages, has been another strategy employed with some degree of success, explains Taylor. This involves taking the batteries out of the hearing aids and placing them in some sort of dehumidifier overnight. There are two types in use by consumers today: the electronic kind that uses a low level of heat to drive moisture from the devices, and chemical desiccants that use some sort of chemical reaction to pull moisture from the hearing aid.

“Both types can be very effective, though the chemical is my favorite and consists of basically a half pint jelly jar with a screw lid, desiccant beads and an open-foam separator,” says Taylor. “A certain number of the beads in the jar are blue versus the rest which are tan in color. The blue beads are indicator beads and when they turn the same tan as the rest, the desiccant has reached its moisture load. When that happens the foam is simply removed and the jar placed in either a warm oven or the microwave (without the hearing aids) on low for a short period. The heat drives the moisture out of the desiccant, recharging it and the indicator beads turn back to blue. I like this system because it works without having to be plugged in and travels very well.”

Taylor explains that, on average, if a patient is diligent about using a dehumidifier, he or she can extend the life of their hearing aid significantly — as much as two years for beachside residents versus about an extra year for those who live more inland. The difference is that the salt and humidity load on the beaches reduce the life expectancy of all electrical and electronic devises as compared to areas with less moisture and salt. So, those with the biggest problem see the biggest benefit from using the dehumidifier systems.

Another moisture-related issue for those wearing traditional behind the ear hearing aids, or the new, “thin tube” open fittings, revolves around moisture from the water vapor inside the ear canal condensing inside the tubing, forming ever larger droplets until they totally plug up the sound deliver tube. Think tiny still, where the inside of your ear is providing the vapor at 98.6 degrees, that then makes its way to the outside of the face where it may be 20 or 30 degrees cooler.

“For some of my patients this has been an ongoing problem, though fortunately one that is as easy to fix as removing the tubing, blowing it out, then reattaching it,” says Taylor.

WATER-RESISTANT ADVANCES
As moisture and corrosion affects the entire hearing-aid industry, there has been a constant push for new configurations and ideas to keep the moisture out of hearing aids. These range from reducing the number of possible entry points and changing the types of controls exposed to moisture, to introducing new hydrophobic materials and coatings deposited right down to the circuit level.

“While not waterproof, the instruments I fit today are most definitely, very, water resistant. And my patients no longer need worry about getting caught in the rain, or forgetting and going in the pool, or the shower, as the aids I fit today can shrug off such assaults with just a little care and maintenance,” says Taylor. “Due to these advances, today’s hearing instruments should be expected to give faithful service for years longer than their predecessors.”