I wasn't sure where to post this, hope this is the appropriate forum.

I need an MP3 player that will allow me to plug in a secondary device (a biofeedback machine, which outputs a continuous tone), so I can listen to the two audio sources at the same time on headphones - the audio playing on the MP3 (in normal stereo) and the audio coming from the biofeedback machine.

Do they make such a beast? Or a cd player w/that capability would do if necessary.

Thanks much,
Harold

Not sure if any portable .MP3 players have a line input (doubt it), but you could easily do this with almost any computer.

Copy the .MP3 to the computer and play with Media Player. Connect the biofeedback machine to the computer's audio input. Use Windows Mixer to control the playback levels through the headphones.

Ah! I have an old laptop w/XP on it. That might be just perfect. Great idea. Thanks very much.

Harold