The 2011X tag links this clip to the modern Sonic.exe horror fan scene built around the X character from the early 2010s creepypasta era. Short, extremely loud screams became a staple of that community and of horror edits generally, in the same tradition as the FNAF jumpscare scream. Clips like this are shared on soundboards because they need no context to work, travel easily between gaming videos and meme pages, and still deliver an instant scare or comic shock even when listeners know it is coming.
About this sound
The 2011X scream sound effect is a loud horror jumpscare shriek from the Sonic.exe fan game world, used for shocking reveals and meme scares.
This is a piercing, drawn-out scream designed to cut through everything else in a scene, lasting just over four seconds. It starts at full volume with a raw, distorted edge that feels startled and furious at the same time, then holds long enough to become uncomfortable. There is no music or dialogue underneath, just the pure vocal blast, which makes the silence before and after it hit harder. Editors use that emptiness to build dread, then let the scream land like a jumpscare that freezes the viewer for a beat.