Crying baby sounds have been a staple reaction effect on soundboards and in video edits for years because the wail is instantly understood in any language. The drawn-out waaa shape works like an audio emoji for complaining, being spoiled or wanting attention. Creators use shorter cuts for memes and longer stretches for pranks, storytimes and family clips, and it keeps circulating because it pairs naturally with disappointed faces, failed attempts and over-the-top sad moments on social platforms.