The ding is one of the notification tones associated with Apple iPhones and iPads, instantly familiar to anyone who has used an iOS device for messages and alerts. Because the sound is heard millions of times a day in everyday life, creators began lifting it into short videos, memes and edits to mimic a phone notification on screen. It spread as a shorthand for a new message, a plot twist or a sudden realisation, and it remains popular because it is short, clean and universally understood without any explanation.