The cash register ka-ching is one of the oldest commercial sound effects in media, dating back to mechanical tills from the late 19th century where the ring signaled a transaction. Recorded and synthesized versions became a staple of cartoons, sitcoms, game shows and early mobile ringtones, including compressed GSM phone tones in the 2000s. That mobile era kept short, bright versions in circulation as notification and meme sounds. It remains popular today because the association is universal, instantly understood without words across languages.