This sound is associated with the dark synth atmosphere of Stranger Things, the Netflix television series that began in 2016. Online, short bassy cues from the show's soundtrack and sound design spread through horror edits, suspense memes and dramatic reaction clips. People keep using this kind of Stranger Things audio because it quickly signals mystery, danger and an 80s sci-fi tone without needing a long setup. It has stayed popular in short-form video where a single low hit can change the mood of a scene instantly.