Public announcement chimes are a familiar part of daily life in Thailand in schools, stations, offices and public buildings, where a short tone warns people to listen before a message is read. Online, creators borrowed that recognisable entry sound as a standalone clip, separating it from any actual announcement so it can be dropped into unrelated videos. It spread through soundboards and meme edits because the meaning is understood immediately, even without words, and it still works as a simple transition into information, instructions or a parody notice.