LFPG airport was placed out in the boondocks north of Paris. The location when it was built was mostly farm land and was very prone to fog especially ice fog in the winter. Now, the airport is surrounded on all sides with all kinds of buildings and industry. In the 60's and 70's jets were pretty loud, but the high by-pass fan engines of the newer planes and other sound abating tech has really kept the noise level down. Since the Concorde is no longer flying even the birds have regained their hearing.  :D