This has happened. The Blob appears to be unaffected by Banshee's screaming.
It was in a Marvel special edition Christmas special. I can't remember the number or anything but I do remember that, and there was a nifty story about the Punisher in it where Microchip dared him to take out his next opponent without shooting a gun, throwing a punch, or doing any type of aggressive act.
This is how i see it going...
1. http://img83.imageshack.us/img83/9636/vblob01xj4.jpg
2. http://img170.imageshack.us/img170/6826/vblob02zc0.jpg
