Tinnitus background noise to one that can be heard even over loud external sounds. The specific type of tinnitus called pulsatile tinnitus is characterized by hearing the sounds of one's own pulse or muscle contractions, which is typically a result of sounds that have been created by the movement of muscles near to one's ear, or the sounds are related to blood flow of the neck or face. Due to variations in study designs, data on the course of tinnitus showed few consistent results. Generally the prevalence increased with age in adults, whereas the ratings of annoyance decreased with duration. Persistent
Tinnitus masker efficacy of a tinnitus masker may depend on the wearer's capacity to experience "residual inhibition," the temporary suppression of tinnitus in response to particular sound patterns. The mechanism of sound masking can be explained by analogy with light. In a dark room where someone is turning a lamp on and off, the light will be obviously noticeable. However if the overhead lights are turned on, turning on the lamp will no longer be as distracting because it has been "masked". The concept that an external sound could suppress perception of an internal one was first realised clinically in the mid