So a while ago I bought a Super Gameboy Commander controller from a japanese website because I was really intrigued by the "speed" button it had. When I got it and tested it out, I noticed that every time you press it, there's this annoying "WHOOSH" sound effect. It kind of ruined the songs when I would use it because who wants to hear crazy WHOOSH's all the time?
Anyways, I just pro-sound modified one of my Super Gameboys and I noticed that the WHOOSH is gone! The WHOOSH must just be something the Super Nintendo produces because it only comes out through the SNES's audio jack.
I know this is kind of a basic thing but someone might find it useful so I made a quick video to show what I mean.