effective perceived noise level

11.17  effective perceived noise level. Level of the time integral of the antilogarithm of one-tenth of tone-corrected perceived noise level over the duration of an aircraft flyover, the reference duration being 10 s. Unit, decibel (dB); abbreviation, EPNL; symbol, L_EPN.

Annotation              The integral is usually approximated by summation, over the top ten decibels of an aircraft noise signal of the antilogarithms of one-tenth of tone-corrected perceived noise level at successive 0.5 s intervals.