television remote control; term dates from the late 1960s when the first tv remotes made a loud click when the buttons were pressed (because they sent an audible high-pitched noise to a microphone in the tv which would then
change channels or volume. The click was actually a small hammer inside the remote that struck a small metal tube which made it
resonate. Each button on the remote
had it's own tube.) The type was discontinued due to the fact that someone dropping their keys or the phone ringing would cause the tv to go crazy and change channels by itself.