tap dance typist (n). One who types so noisily on a PC that you can hear them from across the room (even fifty feet away). The more public the setting, the more annoying the situation. The typing often sounds as if the typing is mimicking a tap dance routine--with the enter/return button getting a big "stomp".
How are we going to get any work done in the library, Jane? That tap dance typist has been putting on a public show for over an hour!