I'm sure other programs do this as well, but a program called Transmit (.torrent downloading program) for Mac allows you to customize the sound it plays when a download completes (it lets you choose from the list of 'mac sounds'). This might also be a helpful tool for ingesting cards.
I did a search to see if there were already any requests for a feature like this and one result showed up where Kirk said "We could also have it play a sound of your choice," when talking about the ingest complete dialog.
Just wondering if this idea ever got anywhere.
I'm running Mac v4.6.3