Horn made famous at the 2010 World Cup

• Cape horn?
• Buzzer sounded during a match
• Football match horn
• South African horn, seen at football matches
• Infernal South African buzzer
• Stadium ear piercer
• Loud horn much heard during the 2010 World Cup in South Africa
• Horn banned from the 2014 World Cup

Wiktionary Word definitions in Wiktionary
n. A trumpet-shaped horn, now usually plastic, that produces a loud buzzing sound.