> What's the term for a persistent ringing or noise in your ears?And the answer: tinnitus. Photo credit: New AtlasTinnitus involves the sensation of hearing sound when noexternal sound is present. According to the Mayo Clinic, it's a fairly commonproblem, affecting about 15 to 20 percent of people. It can be caused by anunderlying condition, such as age-related hearing loss or injury to the ear, butit's usually not a sign of something serious.Most people have experienced some form of tinnitus, however short lived it maybe. Attending a loud concert or watching a loud movie can trigger tinnitus thatfades away after several hours. If the condition persists for over six months,it is then considered chronic tinnitus, a condition which usually requiresmedical diagnosis. While more rare, effects of chronic tinnitus can be greatlyreduced or eliminated by a variety of treatments. Our ears are complex organs that allow us to take in many stimuli at once. Theyare always collecting information -- even when you’re asleep! The ears containsome of the smallest, most delicate bones in your body. While these bones aresmall enough to fit on a penny, their structure and the surrounding valves haveevolved to support the sensory neurons responsible for the sensation of hearing.To learn more about the way we hear, check out the video below.