What's the box for?

I was changing the alternator on my 98 S10 today and when I pulled the plastic tube off that goes to the air cleaner, I noticed it had a tube running downward from it and it was connected to a plastic box. I couldn't figure out what the box was for. It doesn't appear to have any use. Anybody know?

ive got the same thing, i thought it served no purpose so i took it off and bought a piece that covered the hole and nothing has gone wrong yet and ive driven it at least 10000 miles like that

I was a little reluctant to admit it but I left mine off too. I think I glued a plastic cap on mine. The only possible thing I can think of now is that it might cut down on intake turbulance. I think they have these on dirt bikes. I don't know of any other vehicles that use this, though. Joe

they put those boxes on to tone down the noise of the the air going through.. most of the full size trucks have them too