The sound comes from Apple's iPhone system audio, the short tap heard when typing on the on-screen keyboard or locking the device. As iPhones became the most common phone in many creators' hands, that tiny click became a shorthand for phone use in general, not just for Apple devices. Editors began lifting it from screen recordings and sound libraries for online videos and tutorials, where a real phone sound sells a texting or unlocking moment faster than any narration. Its familiarity keeps it in regular use for phone-based scenes.