I have and aging aunt-in-law who used an old fashioned hearing aid with separate ear-piece and amplifier.
This works very well for her apart from when she uses the phone. To do so, she has to remove the amplifier from somewhere under her cardigans and hold it over the earpiece of the phone, a process that takes a little time and often results in callers hanging up before she can initiate a conversation.
Life would be simpler if her phone earpiece could be linked up to a loop aerial that covered a wider area so that she wouldn't have to fiddle with her hearing aid. Do any phones exist with the appropriate socketry to allow them to be connected to a loop-aerial amplifier? She already has a phone with a built in inductive coupler but that's not a lot of use with the old chest mounted amplifier that she uses.
TIA
Tim