If I'm not mistaken, AGISB plays only 3 voices...
The noise voice is not played, I'm not sure why...
Could be because AGISB doesn't supports it, or because the sound resources don't use it.
Anyway, if you have a game with a sound that uses the noise voice, I would be very interested... since I wrote an AGI sound editor that does not support the noise because I couldn't figure out how to use it (or how it should sound)...