A mechanical wave such as sound needs a medium to travel through. This is why they say that in space, no one can hear you scream (because space is a vacuum and no medium exists). On the contrary, light can exist in wave or particle form. This is why we have the ability to see beyond the realms of the Earth.
The transmission of sound depends on the existence of a material medium (solid, liquid, air particles) where the vibration of the molecules are perceived as a sound wave, which are converted into mechanical waves in the human ear, to be later perceived by the brain.
Umm the rocks warm up until it becomes a not rock anymore and becomes really hot then it get so hot it starts coming out of a mountain called a volcanoe