wiring phone to ring to headphones

Hi,
My dad is 90 years old and totally blind. He frequently listens to the radio and talking books via headphones, however he cannot hear his phone ring with the headphones on. Do you know if/how I could wire his phone to ring through the headphones (while the radio/bookplayer is playing) to alert him that he has a call?
Thanks in advance,
Fredsel

when the phone responses to the call, it produce good electromegnetic field to the surrounding, you may think of a device to be installed in the intermediate amplifier / mixture so that it will be activated by this radio signal and give a mute to the audio he is listening and may play back another audio or beeps.

Get him a set of open air headphones, and perhaps an amplifier for the phone, they make simple plug in adapters for the phone that will sound an alarm that no one should be able to miss, even with headphones on.

You probably could create an electronics circuit that would do what you want but it depends on your level of expertise with electronics if it'd be practical.

Ok, Thanks, good suggestions. Maybe just a louder ringer would do it. Fredsel