The clarion was a long, straight medieval trumpet used for signalling in battle and ceremony, and its name comes from the Latin clarus, meaning clear. Over time the phrase clarion call came to mean any powerful public appeal or summons, not only a literal trumpet blast. Short recorded fanfares based on that tradition are now widely reused online as announcement sounds, where the familiar rising brass pattern instantly tells an audience to pay attention, gather round or prepare for something significant to follow.