Cassette answering machines were a common part of home telephones through the 1980s and 1990s, recording messages on a small tape after playing a greeting. The short beep was the cue that recording had begun, and anyone who grew up with one recognises it instantly. As voicemail moved to phones and digital services, the sound survived online as a short soundboard clip, shared for prank calls, skits and retro edits. It still works because it needs no explanation: one tone tells listeners to leave a message after it.