The range of sounds that many very credible reporters have attributed to BF is so great that it doesn't seem really possible to characterize what's normal for them, or what's uniform behavior (so that's why I quoted SY and daveedoe; I thought those were great points).
I've only heard two vocalizations in my brief experience so far out there with our friends, and those vocalizations were growl-like sounds, on two separate occasions.
So in that three-blind-men-and-an-elephant story, I've barely touched a whisker on the elephant. And I think a lot of us -- even more experienced people -- are in a similar position. It's just hard to know the whole story, or to get to a place where one could reasonably conclude the whole story had been told.
PB (and Mockingbird), the guy who recorded these sounds has allegedly been listening to sounds like them for a while now. He says he has connected with the individual making them, so they're not strangers. If what he says is true, he's way past the jumping-out-of-the-tent stage with this, and also past the worst of the fear. He has also said that the sound-making intensifies after he goes into his tent, so he stays in the tent, so as to have more stuff to record.
About these sounds being within the range of human sound (whatever that means, exactly; I'm not an audio expert): I think Sasquatch do make sounds within our range. That's what can make it confusing to figure out who's making what sounds. (That's what you were saying, right, SY?) Scott Nelson believes they can vocalize in our "range", but deliberately excludes that kind of audio from his research, precisely because including it causes too many arguments. He wants audio that's unambiguously, indisputably theirs, and he can only do that by excluding audio that could have been produced either by them or by us.
But again, that doesn't mean they're not fully capable of creating sounds that exactly replicate what a human would (or could) produce.
Bipedalist, your comment about the thing that's missing from the audio echoes what Alex has said, too, and your two comments are the only ones that give me pause here.... And I appreciate your not saying more about the thing that's missing, and your reasons for not saying more.
But it does make me nervous.