Lead is used to block X-rays. Couldn’t it block tightly formed waveleghths up in the high Hertz registers, like dare I say, brainwaves? nimwhits, like it’s a joke joshhoustonis: Obviously the fact that knowing lead isn’t considered insulation makes you Einstein. I sude the term losely meaning to pad the inside of my walls with sheets of it. Of course you wouldn’t know that. That is why you’re in the insulation buisness and not in the study of science.