Is the battery in a hearing aid or similar device consumed more rapidly in the presence of loud noises? Less? In other words does the hearing aid “work harder” in loud noise ambiance?
Not that I’ve ever noticed. I use #10 hearing aid batteries. Each lasts around 48 hours, but there is a huge variance. I’ve had a few that are dead in an hour and a few that last 72 hours. But I’ve seen no difference between library and concert use.
With a digital hearing aid that actively filters loud background noises, I’ve noticed a decrease in battery life if the aid is continuously filtering. Not a huge difference, but enough to notice. Of course, I haven’t bothered to actually test to confirm this, it’s just something I’ve noticed with my aid.
I use #312 batteries which last about 2 days of calendar time. I’ve noticed a lot of variation in battery life time, but I’ve always attributed it to battery quality. Like a previous poster said, I’ve seen batteries last less than a day, and more than 3 days. I’ve never attributed it to anything other than battery variability.
J.
Why don’t hearing aids come with batteries that don’t need to be removed and can be charged while still in the hearing aid?
I saw (blast! I can’t remember his real name) the Six Million Dollar Man advertising just such a thing recently. At night, you plugged in a case, set the hearing aids in the case, and they charged as you slept. Considering that many people who use hearing aids have trouble seeing and handling things as tiny as hearing aid batteries, I don’t understand why this isn’t more common.
For the simple reason that those kind of batteries you’re talking about aren’t nearly as safe as normal batteries. They’re also less stable and run hotter. You wouldn’t want an explosion or leakage inside your ear canal, would you?
^cost? The hearing aid I wear in my left ear (my right is beyond help) cost a bit over 3k. Bump it another grand and I might have thought again about purchase.
ETA: that was to Cathode, MD.
Kandinsky That would explain it. While I tend to enjoy explosions, I can see why the average person might want to avoid them.
Kayaker my degree from the secret school hidden under the Franklin Institute was a PhD, not an MD.
Probably because a primary battery (i.e. non-rechargeable) has higher capacity than a secondary (rechargeable) battery of the same weight and size.
You know, I’m new here. I should learn how to talk on this forum. I signed up after reading the site for only an hour. I get now that one needs to put some thought into and source a claim if possible, explain better and be more polite. So, sorry for the above.
Kandinsky What exactly are you apologizing for? While more information (like why exactly rechargeables run hotter) would have been good, you delivered what seemed to me to be a factual answer based on your knowledge. I didn’t perceive any rudeness.
oh and welcome to the Dope!
What?
Now I have to apologize again, for my lack of confidence. Thanks for the welcome. 
A more technical question is, does the amplifier waste power inside itself when it produces low voltage ?
I was going to research what type of amplifier would be used but by the time I got to bipolar amplifiers the topic was driving me crazy. See
But anyway, given the great knowledge of these things, I’d say the amplifier would be designed to be efficient and should be able to conserve power until its required to make loud noise…