Virtual Sonic Fence

The latest in non-lethal stopping technology, the Virtual Sonic Fence creates a barrier which causes loud, annoying sounds when breached. It's also highly portable, folding up into an easily-carried form which can be unlocked using a numeric code. Getting the unlock code wrong three times locks the user out of the device.

Fiction

Rescue Bots Academy cartoon

Heatwave placed the device in the care of Hoist, who memorized the code to unlock it by remembering the tune which the tones on the keypad made. Unfortunately the tune proved to be an earworm, and he and the other recruits had trouble concentrating on their work with it filling their heads, so they excised it by playing other music. Doubly unfortunately, this meant that Hoist forgot the unlock code to activate the device, and when the recruits were sent to the planet Herboo, he was unable to activate the device when they needed it. The recruits had to take a moment to remember the tune, and Hoist successfully used to to ward off the karknoid beetle. Tune Out