To my thinking, the most fascinating aspect of this is how we didn't already know. Humans have had noses for, like, decades now; you would think that (a) we would already have quite a good handle on what they can and can't do, and (b) those capabilities would be intuitively and straightforwardly testable, in equivalent circumstances to how they would be naturally used. It didn't require a great leap of logic to make an eye chart, or to play quiet sounds into headphones... but testing this required nontrivial mechanical and biomedical engineering work.
It seems a little like this capability is "vestigial, but only just". As in, you wouldn't have to backtrack very far through the primates to find one that could do this, knew it could do it, and needed to do it... and despite that we don't really, there hasn't been enough time for genetic bit-rot to set in and screw up the fundamental ability.