I don't have an eMac but i assume they have an inbuilt microphone - if you are running a current model(OS) hopefully you have Sound Studio which will let you record your voice- I don't have a microphone on this PowerMac to test the idea-- I am only " hypothesising- or supposing-- or guessing :-)
Try recording your voice message and create your CD with the messages between tracks-worth a try
good luck - and if you undertake this mission we will disavow....
Ron