From the report "The most distinctive clinical aspects of the illnesses were the nature of the onset and the initial features: the sudden onset of a perceived

From the report "The most distinctive clinical aspects of the illnesses were the nature of the onset and the initial features: the sudden onset of a perceived loud sound, a sensation of intense pressure or vibration in the head, and pain in the ear or more diffusely in the head. Most individuals reported that the sound or these other sensations seemed to originate from a particular direction and were perceived only when the individual was in a specific physical location" The directed radio frequency hypothesis seems quite plausible.