Yeah, the first, useful clause does that, but the second clause is different and doesn't confer anything.
Everyone detects the invisible creature though -- it's not hiding. The only way the ranger ability makes sense is if you totally ignore the designers input and say that all invisible things cannot be noticed, even if they don't hide. So far, you're the only person in the thread that's asserted this as a baseline (and kudos for that, btw, I appreciate your clear stance on the matter).
We're talking about feral senses, right? Because either the book is wrong (which is an odd stance to take) or the opinion of the authors is that there are times where an invisible creature can be heard but their exact location can be narrowed down with any precision.
I think the latter is just as plausible if not more so. Just because you know there's someone is there because you heard them (so therefore not hidden) doesn't mean you automatically know where they are within 5 ft. Or of course just pick and choose which parts of the book are the rules and which are not.