Tinnitus masker issues associated with use of tinnitus maskers: the "safe" level of continuous sound depends on the duration of the sound. For maskers worn continuously, or most of the day, a safe level is no more than 70db, in accordance with EPA maximum safe exposure level for 24-hour environmental sound. Maskers louder than 45db or so (the ambient background level of an average home living area) may start to interfere with understanding conversation (about 60db). Masking of high frequency tinnitus (>6,000hz) is difficult because of the resonance characteristics of the human ear as well as high frequency limitations of in-ear devices.
Tinnitus retraining therapy called it masking), an integral part of TRT, found no convincing evidence of the efficacy of sound therapy in the treatment of tinnitus. A summary in The Lancet concluded that in the only decent study, TRT was more effective than masking; in another study in which TRT was used as a control methodology, TRT showed a small benefit. A study which compared cognitive behavior therapy (CBT) in combination with the counselling part of TRT versus standard care (ENT, audiologist, maskers, hearing aid) found that the specialized care had a positive effect on quality of life as well as specific tinnitus