A measure of SOUND PRESSURE LEVEL, given the symbol L. Various subscripts define the nature of the measurement, most commonly as follows:L10: sound level exceeded 10% of the time (PEAK LEVEL)
L50: sound level exceeded 50% of the time (average or mean level)
L90: sound level exceeded 90% of the time (ambient level); see AMBIENT NOISE LEVEL
LA: sound level in DECIBELs measured on the A scale; see SOUND LEVEL METER
Leq: EQUIVALENT ENERGY LEVEL
LNP: NOISE POLLUTION LEVEL
Ldn or LDN: day-night equivalent noise level; see EQUIVALENT ENERGY LEVEL
See: LOUDNESS LEVEL, NOISE, PERCEIVED NOISE LEVEL, SOUND LEVEL, TRAFFIC NOISE INDEX. Compare: DAMAGE-RISK CRITERIA, HEARING LEVEL.