Drying rechargeable hearing aids

The dryers are just flat good maintenance for hearing aids. When the rechargeable hearing aids came out I was ready to jump on board until I remembered having itchy ears all the time before using a dryer/sanitizer.

@jn.richards said:

Phonak Marvel 90

I believe these Marvel hearing aids1 come in models which use a 312 or 13 size battery. Is it too late to take them back and exchange them for a model that uses a replaceable size 312 or 13 battery? I suspect there may be a cost reduction, as well as a gain in user convenience.

Many thanks for replying. A helpful suggestion but unfortunately no longer an option

Thanks for replying. Unfortunately my Marvels were supplied with the mini charger. I am reluctant to buy the charger you refer to which takes tablets as I gather they’re less effective than using UV and the charger itself costs more than double the price of an ultraviolet box.

Rechargeable Phonak’s are $100 more each. I have new replaceable 70 with 13 battery. Batteries are good for 2 weeks which includes streaming. I’m considering going with the rechargeable. I’m still within the trial period, I just have to pay the $200.

I don’t have HA’s with rechargeable batteries, and for various reasons I would not buy them. That said, it seems to me that if the rechargeable batteries stay inside the HA body when they are being recharged there will be enough waste heat generated to warm them up and dry them out, providing there is reasonable ventilation to get rid of the warm humid air generated. In other words if the recharging system is well designed there may not be any need for anything more.

Not sure that the dose and duration of heat is sufficient given that there are few chargers that are specifically designated as drying also. I am aware of only my charger that is so described.

If any charger could also dry, I doubt that manufacturers could resist the opportunity to add drying to their list of “features”.

My dryer only runs for 20 minutes or so. I usually use it while showering.

@jn.richards said:

As I live in central Italy where summer temperatures are in the mid thirties Celsius

What’s the humidity like under these conditions? If you look up a Mollier diagram (there’s an Android app called that, too), you will find that at any humidity up to 83% there will be “much evaporation” and from 83% to 97% humidity, there will be normal evaporation at a dry bulb temperature of 32.4 deg C or above. At any humidity below about 68% with temps in the mid 30’s C, you will have “Very Much Evaporation.” So you’re essentially living in a big dry box in central Italy. Drying your HA’s out just by sitting out will ~prevent microbial growth outside your ears. Since you’re not sterilizing the inside of your ears, when you put the HA’s back in, there will still be the same microbial fauna there that there was in your ears yesterday. The most important thing is probably just to use the same degree of cleanliness with your HA’s that you would use preparing your food, e.g., wash your hands before handling, work on a clean, new piece of paper towel or a clean cloth, etc.

Can anyone quote chapter and verse from an OEM HA manual on the need to dry HA’s in a dryer or sterilize them with UV (or by any other means)? My ReSound Quattro manual has no such instructions other than not to expose the HA’s to liquids or humidity over 90% - and it even mentions exposure to direct sunlight (UV) can lead to degradation of the plastic components in the HA’s.

Instructions for Quattro Maintenance (p.34 of RIE961 manual)

1. Keep your hearing aids dry and clean.
2. Wipe the hearing aids with a soft cloth after use to remove grease or moisture.
3. Do not wear your hearing aids when putting on cosmetics, perfume, aftershave, hairspray, suntan  lotion etc. These might discolour the hearing aid or get into the hearing aid causing damage.
4. Do not immerse your hearing aid in any liquid.
5. Keep your hearing aids away from excessive heat and direct sunlight. The heat may deform the shell, damage the electronics and deteriorate the surfaces. (emphasis mine)
6. Do not swim, shower or steam bathe while wearing your hearing aids.

(note for list item 5-rechargeables might be more sensitive to the heat exposure component than disposables)

Every morning any wax that was on my molds when I removed them the night before is always very dry-I don’t use a dryer or a sterilizer and I wear totally occlusive molds. Letting the molds dry out overnight makes them easier to clean the next day and I don’t need a dryer to do it. Where I live in Texas, the humidity can often rise above 80% at night outside, especially in the spring and fall, but I’ve never seen the humidity go above 70% inside our house and it’s usually in the 45% to low 60-ish% humidity range. According to the Mollier diagram app, even at 16 deg C, there will be normal evaporation at 65% humidity. We heat and air condition our house very little. I should imagine that anyone who heats and air conditions their house like the typical American has an even drier indoors and even less need for a special dryer since they’re living inside a big dry box called the American house (unless you deliberately rehumidify the air as some do).

@jim_lewis Agree with almost everything you said and certainly the main thrust of it. However you lost me a bit about letting your hearing aids dry overnight preventing bacterial growth. Source? It’s not that I think bacterial growth is a big issue, but I’m skeptical that there’s any evidence that letting hearing aids dry out is enough to stop it. I would think earwax, even “dry” could be adequate growth media for some bacteria. But to your main point, I agree that people worry way to much about drying their hearing aids.

@MDB said:

However you lost me a bit about letting your hearing aids dry overnight preventing bacterial growth. Source?

Here’s a Wikipedia article on drying to either inhibit or kill microbes (inhibiting, i.e., “preventing,” in food preparation and “killing” in dealing with sewage sludge): (life depends on water) - some bacteria can enter into a spore state on drying but since that’s a dormant state, one is certainly inhibiting further growth by drying such bacteria)

Drying2

Drying is a mass transfer process consisting of the removal of water or another solvent by evaporation from a solid, semi-solid or liquid. This process is often used as a final production step before selling or packaging products. To be considered "dried", the final product must be solid, in the form of a continuous sheet (e.g., paper), long pieces (e.g., wood), particles (e.g., cereal grains or corn flakes) or powder (e.g., sand, salt, washing powder, milk powder). A source of heat and an age In...

Edit_Update: The following info about “water activity” in foods vs. microbial growth is interesting. The second table shows how dry, in terms of water activity, something has to be to inhibit various types of microorganisms. Perhaps we could consider fresh ear wax to have the approximate fat/moisture content of peanut butter. But at any rate, the table shows that something does not have to be completely dry to inhibit most bacterial growth. It only needs to have its water activity sufficiently reduced.

http://www.foodsafetysite.com/educators/competencies/general/bacteria/bac5.html1

Further_Edit_Update: Don’t know how sound any of the studies are but here’s the Wikipedia take on any possible antimicrobial properties of earwax:

Earwax

Earwax, also known by the medical term cerumen, is a waxy substance secreted in the ear canal of humans and other mammals. Earwax can be many colors, including brown, orange, red, yellowish, and gray. Earwax protects the skin of the human ear canal, assists in cleaning and lubrication, and provides protection against bacteria, fungi, particulate matter, and water. Major components of earwax include cerumen, produced by a type of modified sweat gland, and sebum, an oily substance. Both compone...

I’ll buy that “drying” reduces bacterial growth, but I’m not convinced that overnight drying is enough to do it. It may be, but I think overstating claims lessens overall credibility (my bias)