How is ultrasound like regular sound?
Ultrasound behaves very much like audible sound. It travels through air as a pressure wave and is reflected off walls and other solid surfaces. Ultrasound will penetrate porous materials like cloth because of the air spaces between the cloth fibers. For example, ultrasound will go right through a thick terrycloth towel. A good way to determine if ultrasound will go through a material is to cover your ears with the material and see if you can hear sound.
