Industrial noise 2007 LDEN of the Lyon Metropolis

2007:
date of reference of the sound source.
2012:
approval of the noise mapping deliberation map Lden Index in dB(A):
overall noise for a day.
(L=level (level), d=day (day),e=evening (evening),n=night (night))
Split the day into three periods:
the period of the day runs from 6 a.m. to 6 p.m.,
the evening period runs from 6 p.m. to 10 p.m.; it is weighted by a factor of 5,

the night period runs from 10 p.m. to 6 a.m.;
it is weighted by a factor of 10.