How he handles it: not well. Not at first. All Radar does is clap his hands over his ears, like he's forgotten altogether that he's the one controlling the noise. That he can do more than react; that in this, he isn't merely a receiver.

Five seconds' worth of his ears ringing almost as bad as they did when Mendel messed with him, though, and he remembers. Oh. We're inside my head. If I want it to stop, then I'm the one who's gotta do it.

Grimacing, Radar peels one hand away from his ears to touch the dial again. Slowly, slowly, he inches it the other way, closer to where it was before, and some of the screeching begins to dim.