Tinnitus is an internally generated noise perceived by the listener as a ringing or roaring sound. This sound is not an externally (outside of the head) generated sound. Reactions to tinnitus vary from slight annoyance to incapacitating.
While tinnitus typically begins with a hearing loss, it is not exclusively an auditory problem. It is a result of neurological changes within the auditory system and within the parts of the brain that influence conscious attention and emotional state. No single explanation applies to all cases, but the process outlined below describes one of the more commonly accepted theories about what causes tinnitus.