The exact origin of this short clip is not clearly documented, so it is best understood through how people use it online. The repeated 'ei' call is a familiar way to get attention in Mandarin-speaking communities, and the clip's very short length makes it easy to drop into memes, reaction videos and short-form edits. Because it needs no translation to be understood, it travels well between different audiences, working as a universal nudge. Its popularity comes from that simplicity: five quick sounds, instantly recognisable, that can interrupt, tease or call someone out.