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).
Amplitude measurement â¢ Sound pressure is measured in decibels (dB) on a log 10 scale relative to a reference level â¢ dB = 20 log 10 P 1 /P r where P r is a reference pressure level, usually the threshold of human hearing at 4 kHz.