Industrial noise – Areas where limit values are exceeded, from 22h to 6h (indicator Ln)

**Strategic Noise Map** Data produced by Impédance engineering on behalf of the metropolis Aix-Marseille Provence Industrial noise according to the Ln indicator for type C maps on the Aix-Marseille Provence Metropolis. Results of acoustic modelling calculations. Type C map locates areas where limit values are exceeded. The value of the noise index Ln “Level night”, expressed in weighted decibels A (dB(A)), represents the level of noise exposure at night.