Tinnitus (“TIN-a-tus” or “Tin-EYE-tus”) is the medical term for the sensation of hearing sound in your ears or head when no external sound is present. In most cases, tinnitus is a subjective noise, meaning only the person experiencing it can hear it. Typically, people describe the sound as “ringing in the ears,” though others describe it as hissing, buzzing, whistling, roaring and even chirping. Tinnitus can be sporadic or constant, with volume ranging from subtle to debilitating.