FeedBack
If you’ve ever been to a live music show or played music yourself, you may know how piercing the live feedback sound is when the sound equipment acts up. It usually causes everyone in the room to jump in fear and protect their ears.
When a neighbor refused to turn down their loud music, a musician got his revenge by creating feedback, turning it up loud before he left for an 8-hour shift at 5 am. Needless to say, they respected his wishes thereafter.