Can you post a picture of the current overflow box, specifically the weir?
Edit: Nevermind, just saw your other thread.
You could try the glass-holes box.
If it were me, I would first remove the current box and cut the teeth off the weir, sand it smooth decreasing grit size. Attach plastic gutter guard inside the box. Both the sides and top to keep anything from entering the box and possibly clogging your drain. The gutter guard can be purchased at Ace Hardware. Doing this will double your surface skimming. The Teeth on the weir are actually spreed apart quite a bit. Also it does have a feed pipe from below the box that water flows up so its not just suface skimming. Not sure how I like this.
Where is the noise coming from? The box or the drain? If it's the drain there's a few options to reduce noise. Drill a larger air vent and stick an RO line deeper in the drain to allow more air to escape. Cut a larger whole for a larger bulkhead and larger drain pipe to handle more volume or put a valve on the return line to dial back the flow. The noise is coming from both the drain and the sock holder. This actually does not have a air vent in it and was thinking about putting one in there to see if that helps.
Also it appears your drain terminates above the water line in the sump. I would submerge it 1" below the water line. That will muffle a lot of noise.