In space, no one can hear you scream… because sound is a pressure wave that needs a medium (air, water or solid) for transmission and space is (almost) a vacuum. The pressure wave causes particles in the medium to vibrate, which in turn causes adjoining particles to vibrate, and so the sound spreads. The further apart those particles are the easier it is for the pressure wave to pass through it. Which is why sound is transmitted more easily through air than through concrete. It therefore follows that if we want to slow (or stop) sound transmission then we need to slow (or stop) air movement, which is precisely what thermal insulation is intended
