Sound Pressure and dB L_p (Sound Pressure Level)

Abstract

In virtually all acoustical level measurements, a reference pressure of 20 µN/m² (20 micropascals) is used to determine dB L_p. The relevant equation is:

$$ dB\;\left( {dB} \right) = 20\log \left( {P/{P_0}} \right) $$

((1.1))

where ${P_0} = 20\mu N/{m^2}$. An equivalent quantity in the CGS system of units is.0002 dynes/cm².