SimpleSound can handle that. I'm not sure where it resides on the hard drive, just do a search for it. It's part of Mac OS 9. SoundJam MP Plus can do it too.
First, you will use the sound-in port on the computer. Use the sound control panel to set it up.
Next open simple sound. Close the Alert Sounds window and select new from the file menu.
Record away.
One more thing, these file can get pretty big, so when you're done you may want to convert them to MP3's with QuickTime Player or SoundJam.
[This message has been edited by GORDYmac (edited 10-19-2000).]