Tinnitus is usually described as a ringing in the ears, but it can also sound like clicking, hissing, roaring, or buzzing. Tinnitus involves perceiving sound when no external noise is present. The sound can be very soft or very loud, and high-pitched or low-pitched. Some people hear it in one ear and others hear it in both. People with severe tinnitus may have problems hearing, working, or sleeping.
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.