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 retraining therapy large proportion of dropouts; reported 'success' ratios may not take these subjects into account. There are few available studies, but most show that tinnitus naturally declines over time (years) in a large proportion of subjects surveyed, without any treatment. The annoyance of tinnitus also tends to decline over time. In at least some, tinnitus spontaneously disappears. A Cochrane review found only one sufficiently rigorous study of TRT and noted that while the study suggested benefit in the treatment of tinnitus, the study quality was not good enough to draw firm conclusions. A separate Cochrane review of sound therapy (though they