The Codec sound comes from the Metal Gear Solid series, where the Codec is the in-game communication system used for radio conversations between characters. The incoming call tone became especially memorable through Metal Gear Solid on PlayStation and spread widely in gaming culture, meme edits and short videos. People still use it because a few beeps instantly suggest secret instructions, urgent contact or a dramatic interruption. Its retro game audio and strong association with stealth missions make it easy to recognize even in very short clips.