Noise isolating metals

Pet or kid if its hot they will only touch it once and then, problem solved.

Skip the cages. All these metals vibrate. All you will accomplish is adding that vibrational signature to your signal. Stainless steel is the most neutral sounding. But people who like this stuff tend to prefer brass and wood. Probably since these are already used in musical instruments because we like the sound. I don't like adding (or subtracting) anything but if adding something you like is what you like then go for it.