The man at the next desk, back from vacation, says you can't hold the ocean up
to your ear and hear sea shells.
Another joke which one can easily perpetrate goes like thi
Fill a plastic, or rubber, tube with water. Hold the tube
vertically up into the air and with the thumb of one hand
plug up the bottom hole of the tube and place it next to
your ear (hide the fact that you are plugging the hole)....