In Cuba, the U.S. State Department says a group of its diplomats in Havana suffered severe hearing loss that intelligence officials believe was caused by an advanced sonic device. The bizarre incidents began last fall, when workers at the U.S. Embassy in Havana began complaining of headaches and deafness. Many were forced to leave their posts early due to their illnesses. U.S. intelligence officials concluded the hearing loss was due to a sonic device operating outside the range of audible sound, which was likely planted in or around the homes of the diplomats. On Thursday, Canada said at least one of its Havana-based diplomats was treated for hearing loss, as well. Cuban officials deny any involvement and say they're cooperating with U.S. officials to investigate the incidents. Some are talking about a possible third-country involvement.