The blaring, grinding noise jolted the American diplomat from his bed. He moved just a few feet, and there was silence. He climbed back into bed. The agonizing sound hit him again. It was as if he'd walked through some invisible wall cutting straight through his room. Soon came the hearing loss, and the speech problems, symptoms both similar and altogether different from others among at least 21 US victims in an astonishing international mystery still unfolding in Cuba. New details learned by the Associated Press indicate at least some of the incidents were confined to specific rooms or even parts of rooms with laser-like specificity, baffling US officials who say the facts and the physics don't add up. Suspicion initially focused on a sonic weapon. Yet the diagnosis of mild brain injury, considered unlikely to result from sound, has confounded the FBI, the state department and US intelligence agencies involved in the investigation. Some victims now have problems concentrating or recalling specific words, several officials said, the latest signs of more serious damage than the US government initially realized. The United States first acknowledged the attacks in August - nine months after symptoms were first reported. The cases vary deeply: different symptoms, different recollections of what happened. In several episodes recounted by US officials, victims knew it was happening in real time, and there were strong indications of a sonic attack.