Soundproofing is the process of lowering the intensity of a sound by surrounding the source of the noise with noise absorbent materials or surfaces. Any means of reducing the sound pressure with respect to a specified sound source and receptor can be considered as soundproofing. Soundproofing for cars is the treatment of a surface to create a barrier to stop noise from passing through this barrier to the other side. The sound proofing products are often used in the door cavities, boot, bonnet and undercarriage area to damp excess vibration of the panels of the car.