Better known as the Low Bork, a Hanna-Barbera sound effect. The sound has been featured in SpongeBob, which usually plays when they're sad.
SpongeBob: I guess I'll have to move back with my mom and dad. shown a picture of SpongeBob's parents smiling
Patrick: No, wait a minute, no you don't. BOO-WOMP! shown picture of SpongeBob's parents frowning We can build you a new house!
Racism, it means you are racist.
Person 1: Damn, I love being a middle aged white father of 3 in suburban America, truly we are at the height of civilisation. Boo-womp.
Person 2: *Vigorously shits themselves and dies*