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).
For example, if we measure a sound pressure of 0.4 Pa, we can determine the SPL in dB: So a pressure change of 0.4 Pa equates to about 86 dB. In case you do not want to do the math on all of our examples above, here is that same table, now including sound pressure level. As you can see, we now have a range of numbers that seems more convenient â from 10 to 150 â instead of a range from a very, very, small number to a number in the hundreds.