Generator Db how loud is it?

I received from C.B. a copy of that Honda Brochure Page he was referring to that claims Honda generator noise measurements are taken at a distance of 3 metres ... and here's a close up of the bottom of that page which substantiates the claim. The question now is why does Honda Canada indicate on it's webpage 1.5 to 7 metres, why does Honda USA say nothing regarding distance, and why is this brochure info indicating 3 metres so difficult to find? I've PM'd robert_at_honda in hopes he may join in on this discussion and offer some clarity on the subject as I still find it hard to believe Honda adopting a 3 metre standard AND would like to know, if this is indeed the case, the reasoning behind it.