Acoustic Recoil

I found a shiny metal coil jutting straight out of the baseboard by the door. Naturally, an unexplained spring in the wild demands a field test. I gave it a solid tap with the flat edge of my pixel sword. The thing whipped back with an ear-splitting twang, vibrating like an angry hornet. The recoil buzzed right through my arm and set every single charm at my waist rattling like a frantic tambourine. No hidden passage unlocked, but ten out of ten for audio feedback. Obviously, I had to poke it a second time just to make sure.