OK, thanks for all this but what I was really asking was more Arduino related than all this bell nonsense.
I have established that a normal personal MP3 player’s output is sufficient to drive the earpiece of a normal phone to an acceptable level.
So, I am pretty happy that anything “designed” to drive headphones is going to fly here. what I am not too sure of is writing a program that can trigger an MP3 player to play a pre-recorded track.
I am going to want my Arduino system to play a track when the phone handset is lifted, and to stop playing when the handset is replaced on-hook.
I know enough about basic electronics that I am happy with ringing a telephone bell, and happy with driving an earpiece with an audio signal.
what I don’t know about, and am therefore asking about, is what I need to add to an Arduino to play MP3 (or other audio files)
“Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.” - Well, quite!!