Comment Re:Remember the clicker tv? (Score 1) 77
I have actually read about this.. it was way before my time,though. One of the first remote-based devices for TV's was entirely mechanical and based on higher-than-human hearing sound. You'd press a button on the remote, a knocker would hit one of several 'bells' (probably tuning forks?) and the TV would 'hear' this sound and change the channel.
Apparently it wasn't quite silent, and it did annoy pets.