Introduction: Tinnitus is a sound experience despite the lack of acoustic stimuli in the environment. This study aimed to report the audiometry and biochemical analysis of patients with tinnitus compared with the reference group.

Material and methods: The study included a total of 26 patients aged from 20 to 72 years with diagnosed idiopathic tinnitus and 19 healthy subjects as a control group. All patients underwent audiometric tone test, speech audiometry, distortion otoacoustic emissions product testing, the study of evoked auditory potentials of short latency, and biochemical analysis of venous blood concerning values of activity or concentration of the selected parameters of oxidative stress.

Results: Mean values of activity or concentration of the selected parameters of oxidative stress in the study and control groups showed reduced effectiveness of the body’s natural antioxidant barrier and intensification of treatment of lipid peroxidation. Discussion: There are a lot of factors suspected to generate tinnitus. A lot of them seem to be connected with biochemical disturbances inside the cochlea and in the central nervous system. It will be helpful to set such a battery of tests that contains the predictive indicators of tinnitus. It will be best if it is the battery of standard, not expensive tests of blood.

Conclusions: Proper levels of antioxidants may protect hearing. Glutathione and antioxidative enzymes may protect hearing organs against damage caused by free radicals. A lower level of the antioxidants and associated intensification of lipids peroxidation processes may increase free radicals-associated damage and lead to hearing organ dysfunction.