I don't really see it as that amazing I thik loads of people can do it, think those noises might be like those mosquito boxes we have to get rid of teenagers, cause I'm 20 I'm on the edge between kid (who can hear mosquito boxes) and adult (who can't) I think the cut of age is 23-25 give or take.
The over hearing convos thing is a bad habit that can get me in trouble, but that is awesome and does help out when trying to solve puzzles when the group next to you is just about to figure it out and you add your own ideas to theirs and solve it seconds before ^^