Sound exposure is the integral, over time, of squared sound pressure.
The SI unit of sound exposure is the pascal squared second (Pa2·s).
Sound exposure, denoted E, is defined by where Sound exposure level (SEL) is a logarithmic measure of the sound exposure of a sound relative to a reference value.
Sound exposure level, denoted LE and measured in dB, is defined by[1] where The commonly used reference sound exposure in air is[2] The proper notations for sound exposure level using this reference are LW/(400 μPa2⋅s) or LW (re 400 μPa2⋅s), but the notations dB SEL, dB(SEL), dBSEL, or dBSEL are very common, even if they are not accepted by the SI.
[3]