STRANGE BUT TRUE- Cut it out: Cover your ear to hear better   Q.
What's the trick to cutting out background noise while on your
cell phone in a loud and crowded place? No, sticking a finger in
your other ear won't do it. –C. Stuart  A. Surprisingly, the way
to hear better is to cover the mouthpiece. Though you'll hear
just as much noise around you, you'll be able to hear the caller
better, say Sandra Aamodt and Sam Wang in Welcome to Your Brain.
The human brain, it turns out, is a marvel at picking out the
voice you want to hear from a host of others– the "cocktail
party effect." But the phone (cell or not) makes this harder by
feeding sounds from the room you're in through the circuitry and
mixing them with the signal coming from the other phone.  So now
you have the voice plus distorted room noise coming into one ear
plus the room noise coming into the other. This is worse than
hearing at a cocktail party because both the caller's
transmitted voice and the room noise are tinny and mixed
together. Covering t