In message , Malcolm
Stewart writes
Just thought I'd post this as I've not found any similar information by
Googling "Groups". (Lots of "it's not ethical to meddle" stuff, of
course...)

I've had an NHS behind-the-ear hearing aid for the last few years. It's an
analog type (using a 13ZA cell with an on-T-off switch and rotary gain
control marked from 1 to 4) and this morning it was dead, despite it having
had a new cell fitted a few days ago. It was still dead after I tried a new
cell in it, so do I take it in to my local hospital today for repair and be
without it over the holiday weekend, or do I see if there's anything
obviously wrong with it? Yesterday I had noticed that it wasn't as good as
it used to be, or was that my hearing continuing to get worse...

The tube to the earpiece was clear, but when I examined the microphone area
through a magnifier I was horrified at all the crud which had accumulated,
and after removing a fair amount mechanically, I finished off blasting the
hole with IPA from an aerosol using the fine tube applicator. The visual
difference was impressive, but the hearing aid was still dead. So I dried
the HA on top of my hot water tank for 15 minutes, and it's now as good as
new. I can even turn the gain control down a notch. My guess is that the
crud had built up and stopped the microphone diaphragm from vibrating.

I've no experience with any other HA type, and I'm not taking any
responsibility if your ruin yours; but in my case I've saved two hospital
car park fees, some petrol and I've got my hearing back 3-4 days earlier
than otherwise.


The ultrasonic units from Aldi, that we all rushed out to buy earlier
this year, are excellent for doing the ear pieces - but do detach the
electronics first!!!

Mike
--
Mike Whittome