The patients were assessed at the start of the study for their hearing ability and the severity of their tinnitus. The researchers assessed the degree of severity using established questionnaires, which looked at health-related quality of life, the psychological distress associated with tinnitus and how far it impaired their functioning. Using this information, researchers divided participants into four groups ranked on the severity of their condition.
A common cause of tinnitus is inner ear hair cell damage. Tiny, delicate hairs in your inner ear move in relation to the pressure of sound waves. This triggers cells to release an electrical signal through a nerve from your ear (auditory nerve) to your brain. Your brain interprets these signals as sound. If the hairs inside your inner ear are bent or broken, they can "leak" random electrical impulses to your brain, causing tinnitus.