The 45 minutes aspect is misleading. They haven't been using the room to test that, its just that no-one has spent longer than that so far.
I'm wondering what it is they 'can't stand.' The article text is pretty vague. '“Your eyes don’t feel as comfortable in this room,” Orfield pointed out, adding that some visitors have had hallucinations during or after a spell in there. “You lose your touchstones.” Small wonder, then, that even Orfield spends no more than a half-hour at a time in the 99.99 percent soundproof anechoic chamber, and no one has lasted in there for more than 45 minutes.'
It doesn't match either my experience or my expectation, which is why I asked about it above. If someone had a silent computer to code on in there, could they crank out code for a couple of hours without nuisance, or would something bother them? If the latter, then what exactly would bother them?
First of all, I'm seriously disappointed I can't test this because no computer is quiet enough. Second of all, I can't stand working in sound-proofed rooms. I much prefer working in an environment with (non-distracting) ambient sounds.
But I have no doubt that, properly motivated, you could easily spend an hour in there. Hell, if I had access to one I'd go do it right now just for dumb internet bragging rights.
Not all anechoic chambers are equal, and not all anechoic chambers are necessarily quiet - they're only as quiet as they need to be for whatever it's designed to test (an anechoic chamber designed to test ICE equipment might have background noise levels in the 40-50 dBA range), so be careful about extrapolating your experience to the quietest anechoic chamber in the world.
Have they had open competitions? I feel relatively certain that people would endure in there effectively indefinitely: People can tolerate remarkable things.