transmitting audio through a cordless phone

i have a cordless phone that i would like to use and play music through useing my ipod. how can i insert the audio into the phone? i know that i cannot take a stereo jack and solder leads from that to the terminials of where the microphone is on the phone because the microphone works by changing the resistance.

i also know the circuits that will allow you to put people on hold and play music while they wait but that is attached to the phone line, not the phone. what i would like to do is insert the audio signal into the cordless phone not the base. i'd prefer not to attach a small speaker infront of the microphone as well.

can anyone help?

Modern cordless phones use an electret microphone. It can be switched out and your MP3 player can have its output attenuated and connected instead. You might need to use an audio transformer to avoid hum.