The rain on the Canals levels is deafeningly loud because, for some reason, you decided to set each volume entity to 10 and give them all a range of 2000, so they're audible at max volume through every single ♥♥♥♥♥♥♥ map. You also missed several outdoor areas where there should be rain but isn't, like the first airboat ramp not having rain until immediately after making the jump.