Would love to hear from more doctors or blind people (it IS possible to have Web pages read out loud by a program, right?), but the “getting a better sense of the environment” makes the most sense. I mean, this is something I as a sighted person do–there’s a noise and I can’t identify where it’s coming from, so I move around to get a better send of where it is in space. Or I see something I can’t identify–I’ll change my position to see if a different perspective helps me. I bring up the sight thing because I’m nearsighted AND at the age where I need reading glasses, so sometimes out in the yard I need to change my POV to decide if that’s dogshit on the ground or a piece of bark.
So I imagine that constant slight movement might give a blind person a better sense of where things/people are–they’re triangulating though sound.