A modern device of the German brand Path Medical is used to perform BAER tests, i.e. auditory evoked potentials. The aim of the test is to determine the level of efficiency of the auditory system. The test involves stimulating the hearing organ with an acoustic stimulus. Headphones and acupuncture electrodes are used for the test, which allow to obtain results in a non-invasive way. In response to a sound stimulus, nerve cells in the brain produce electrochemical signals, which are picked up by electrodes. An examination of auditory evoked potentials carried out in a few minutes during sleep or a conscious state.