I think that's something we would have to look at.
The point I wanted to make was that the noise levels at altitude are unlikely to cross any known limits. So obviously any involvement by Health Canada would be appropriate. But compared with the noise in the vicinity of an airport at altitude, you just do not achieve the same noise levels on the ground. So it is unlikely to pass that sort of threshold. I think that's what we've just heard from Nav Canada: it's never really been an issue at altitude.
From some of the changing routes, there may have been a change in noise levels because the areas were not on those flight paths before. But I think you would find they're a long way away from any threshold numbers that typically generate any sort of need to mitigate them.