Small bells have been used for centuries as a simple way to get attention, from schoolrooms and shops to churches and front desks, so their sound is understood instantly in almost any culture. Online, the clean single ring has become a staple sound effect for creators, who use it as a neutral alert that needs no explanation. It appears in short videos, streams, presentations and memes whenever a moment needs marking, a door needs opening or a point needs emphasising. Its familiarity is the reason it still works: listeners know what it means without thinking.