Is it possible? Is there a way to take a small .wav file or similar audio format and save it to an EEPROM maybe and have it play when a switch is pressed? Kind of like how the telephone tones are generated on old touchtone phones?
ISD makes a number of voice chips which can record between 10 and 120 seconds for $5 - $10. These appear to be easy to use, but although I've been meaning to test them out, I have not yet had the oppertunity.
If you just want to play tones - like the tunes old pc games made with the pc-speaker - you can just write code that outputs a certain frequency on a pin - output this to a speaker (with a buffer transistor) and the speaker will play the tone.
If you want to play real music or speech then go for the isd chip