The Skype message sound comes from Skype, the internet calling and messaging service that became widely used in the 2000s for voice calls, video chats and instant messages. Its short incoming-message chime was heard millions of times a day in homes, offices and gaming sessions, which is why it became instantly recognisable even outside the app itself. As clips and reaction videos spread online, creators began reusing the chime as shorthand for any incoming text, and it has remained a popular notification joke long after many people stopped using Skype regularly.