This sound is tied to the "Whassup?" catchphrase that became widely known from a Budweiser ad campaign around 1999, then spread further through quotes, remixes, and parody scenes in the early internet era. Online, people often spell it as wazaa, wazaaaa, or similar stretched variants to match the delivery. It remains popular because it is short, instantly readable as a joke greeting, and works well as a nostalgic reaction clip in meme edits and comedy videos.