"Ringing" int he ears is called tinnitus. It happens when delicate cells inside your ear that send sound messages to your brain are injured or over-stimulated. The brain interprets the electrical signals from auditory nerve as sound. Tinnitus often happens because people expose themselves to damaging levels of sound over long periods of time and do not protect their ears. If you have to shout over a sound to make yourself heard, it is too loud. Other causes can be a plugged ear canal, abnormal blood pressure, allergies, ear infections, medications and even certain foods. If you have persistent tinnitus, you should tell your doctor about it.