Published: 25 November, 2004

Over-stimulation to inner ear causes tinnitus, or "ringing"

Why do your ears ring?

"Ringing" in the ears is called tinnitus. It happens when delicate cells inside your ear that send sound messages to your brain are injured or over-stimulated. These cells have projections on them that look like hairs, and they are called "hair cells". The perception of sound starts when pressure waves moving through the air reach your ears. This causes your eardrums to vibrate, and these movements are transferred to the fluid in the inner ear, where the hair cells are located.

Movement of the inner ear's fluid leads to bending of the tiny hairs on the hair cells. This bending excites the hair cells, and causes them to send electrical signals to your brain through a nerve called the "auditory nerve". Your brain interprets the electrical signals from the auditory nerve as sound. The ringing sound of tinnitus is often a high squeal, like the sound of a computer monitor, but it can also be a low roar, and it can affect one or both ears. Usually your ears ring for a brief time after youve been exposed to loud noise, but for about 44 million Americans, ringing in the ears is a constant and annoying problem. It most often happens because people expose themselves to damaging levels of sound over long periods of time and dont protect their ears. You can tell a sound is too loud for safety if you have to shout to make yourself heard over it. Other causes of tinnitus can be an ear canal plugged with ear wax, abnormal blood pressure, allergies, ear infections, medications, and even specific kinds of food! If you have persistent tinnitus, you should tell your doctor about it.