So @gogogadgetupvote it depends of whether or not they guy that use to live with you was actually blind? That being said, this is something we can all do to an extent, sighted people just think about it less since we have a visual reference. But most people should be able to distinguish between a sound that comes out of a big empty room, vs a small room filled with sound absorbing furniture or something to that extent. Either way I found it extremely fascinating!

I've also heard a story that monks use to sing/hum in the dark monasteries and used this to echo-locate their way around the darkness. But I don't have a source for that unfortunately.