If you've ever seen a Jewish man with strings hanging out of his clothing, this is probably what you were seeing. There is no particular religious significance to the tallit (shawl) itself, other than the fact that it holds the tzitzit (fringes) on its corners.
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average, or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa).
One parameter of the acoustic (sound) wave which is generally used to assess sound exposure to humans is the sound pressure level expressed in Î¼Pa or Pa. Human earâ audible sound pressure levels range from 20 Î¼Pa (hearing threshold) till 20 Pa (pain threshold), resulting in the scale 1:10,000,000.