Understanding tinnitus
Noise-induced hearing loss is the most common cause of tinnitus. Exposure to loud noise for extended periods of time can damage the hair cells of the inner ear, leading to reduced hearing (cue the slideshow of headbanging rockstars running through your mind).
Regardless of where the noise exposure and resulting damage came from, tinnitus is your brain's adaptive reaction of "making up for" the noises it's no longer getting from the outside world. In short: your brain is creating noise to fill the silence.
Other causes of tinnitus include:
Managing tinnitus
Prevention & treatment