If your parents have a "medically recognized hearing loss" (wear hearing aids), then a
free option is a telephone from Call Caption. On incoming calls the screen flashes and the ringer can be turned up or down. The handset can also be adjusted. Therefore you can have the volume low (I haven't tried muting the phone) and still have the screen flash on incoming calls.
RESTRICTIONS: A note from your Doctor
Internet connection (wired or wireless)
If you are not in the room, you will miss the call
Only one phone per household.
AVANTAGES:Call caption available (like in the movies).
TIA-4953 compliant
Connects inline with an answering machine
You can hold the handset to the answering machine and connect to Call Caption and the message will be displayed across the screen.
Address book
FREE
Call Caption website.
I have had the phone for about 5 years or more.
