Some people report it has a throbbing behavior. It can be described as a highly pitched permanent noise. However, in some cases, tinnitus has a clock-ticking sound. Other people describe this sound like a hum. Often, the symptom is the smooth loss of hearing ability. The problem may pop out of nowhere and then disappear suddenly. The level of noise and tone change as well. It is difficult to define the nature and origins of the noise such patients hear.