Ululation is a long-standing vocal tradition in many cultures across the Middle East, Africa and South Asia, where the rapid tongue trill is used to express joy at weddings, celebrations and other happy gatherings. Online, a short, punchy version of that sound has been clipped and shared as the wulululululu effect, often detached from any one video or performer. Its recognisable flutter makes it easy to reuse, so creators keep reaching for it whenever they need instant excitement, mock ceremony or an over-the-top reaction.