My latest foray into Borgifying myself, on TidBITS.
I tried this out for the first time while standing outside of a Starbucks, and suddenly I could hear the footsteps of anyone walking by. Snatches of a conversation at a 20-foot distance. I heard a siren, and then was shocked to see an ambulance pass by three blocks away. Traffic or ambient noise is also amplified, of course, but our brains have had a quarter-million years to learn how to separate out important sound frequencies, and that plus my lip-reading abilities turned me into a rather powerful eavesdropper. Walk into my Starbucks and observe me with my earphones in, and my iPhone with the screen turned off; you’ll probably assume I can’t hear a thing. But I can probably hear you place your order as well as the barista can.