|Vuvuzela, courtesy of Wikimedia Commons.|
Apparently, vuvuzelas sound like "elephants in distress or the buzzing of a bee swarm" and are associated with both permanent and temporary hearing loss. They can also hurt your lips and if you share them, there's the risk of spreading germs.
According to this article, retail stores are ordering 7,500 earplugs in preparation. And if you're watching the World Cup online (or have an equalizer on your TV), here's an article from Lifehacker about how to silence the sound.
Something to keep in mind as you cheer on your team for the World Cup!