Sound Pressure and Intensity

Question	Answer
Sound pressure is the pressure caused by a sound wave	The symbol for sound pressure is ρ
The SI unit for sound pressure is pascal, with the symbol Pa	The unit is named after the French scientist Blaise Pascal
Another important measurement is the sound pressure level	This is a logarithmic measure of the effective sound pressure of a sound relative to a reference value.
Sound pressure level is measured in decibels and have the symbol dB	It is also measured above a standard reference level
This standard reference level in air is 20 µPa	This is considered the threshold of human hearing
To measure the total sound pressure, you have to take the atmospheric pressure into account too	ptotal = pa +ps pa is the atmospheric pressure,and ps is the sound pressure
The sound pressure level can be measured using the equation \(L_p\)= 20 log10\(\frac{prms}{pref}\)	Where prms = the sound pressure being measured, and pref = the reference sound pressure
The decibel level ranges from 0-225 dB	With 0-25 decibels being very faint, and 100-225 decibels being deafening!

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	Created by leonie.examtime over 10 years ago

	Copied by ed.wilson89 over 10 years ago