There are a few techniques to soundproof your house or room(s). In most homes, the insulation is installed in the space between the outer and inner ceiling of your home and can be packed or blown. Soundproofing materials improve energy efficiency and reduce heat energy leakage. They also cut down on sound transmission and reduce the transmission of external noise by absorbing and dampening the sound waves.
You can also install soundproofing materials that reflect or absorb sound transmission on the inside of your house. If you have ever been inside a recording studio, both walls and ceiling are covered with acoustic panels for noise control, made of cones that break up and absorb the sound waves. Most homes, of course, can get away with simpler insulation installed in the ceilings.