It’s called Tappers and Listeners.

The essence is you hear more than your listener.

Think of a song everyone knows (Happy Birthday, etc.) and ask someone if they can “name that tune” when you tap it out on a table.  I know it sounds crazy, just try it.

Did they guess the tune?  My guess is “No.”

Why can’t they recognize it?  Because you can “hear” the song in your head and they cannot.

Think about that for a moment and try another song.  Then have them tap you a song.  Whoa!

For more information read the book Made to Stick.