Tinnitus activity in the limbic system and autonomic nervous system, thus increasing tinnitus awareness and annoyance. There are two types of tinnitus: "subjective tinnitus" and "objective tinnitus". Tinnitus is usually subjective, meaning that there is no sound detectable by other means. Subjective tinnitus has also been called "tinnitus aurium", "non-auditory" or "non-vibratory" tinnitus. In very rare cases tinnitus can be heard by someone else using a stethoscope, and in less rare – but still uncommon – cases it can be measured as a spontaneous otoacoustic emission (SOAE) in the ear canal. In such cases it is objective tinnitus, also called "pseudo-tinnitus"
Tinnitus methods are poorly supported by evidence, there are no negative effects. There is some tentative evidence supporting tinnitus retraining therapy. There is little evidence supporting the use of transcranial magnetic stimulation. It is thus not recommended. As of 2017 there was limited evidence as to whether neurofeedback is or is not helpful. "Ginkgo biloba" does not appear to be effective. The American Academy of Otolaryngology recommends against taking melatonin or zinc supplements to relieve symptoms of tinnitus. In addition, a 2016 Cochrane Review concluded that evidence is not sufficient to support taking zinc supplements to reduce symptoms associated with tinnitus.