There are lots of devices which emit sounds just outside the human hearing frequency range.
For example, most mobile phone power supplies emit a lot of noise around 25kHz (and a few which are faulty drop down below 18kHz and become audible to young people).
I wonder what hearing issues all these devices together might cause?
When my phone is full and still on the charger, the whine is intolerable. Three chargers so far have done this. Not sure if it is the same thing. I consider my hearing sub par and I'm in my mid thirties.
"Coil whine": Look for chargers which don't have this problem. I've heard that Anker has chargers without this problem though I have not used them and can not, therefore, personally vouch for them.
I've never had this trouble with Apple chargers. I've also heard good reports of Anker products, but never tried them myself.
In extremis, you can open up a charger and pot the coils yourself with hot glue, epoxy, or some other nonconductive polymer. Just be sure to disconnect it from power first, lest you inadvertently get your own batteries charged.
Wow, I've never noticed before that my phone charger makes noise when my phone is fully charged,
huh. (Thankfully I can only hear it if my ear is within 1 foot of the charger.)
For example, most mobile phone power supplies emit a lot of noise around 25kHz (and a few which are faulty drop down below 18kHz and become audible to young people).
I wonder what hearing issues all these devices together might cause?