[Registration of the early acoustically evoked potentials using monaural and binaural stimulation (author's transl)].

At seven normally hearing test persons the early acoustically evoked potentials were registered using monaural, binaural and contralateral click-stimulation with a repetition-rate of 10/sec at the intensities of 90 and 70 dB SPL. In comparison to the monaural stimulation the binaural stimulation yields in the mean no significant alteration of the potentials I, II and III at both intensities. The mean enlargement of potential IV by binaural stimulation amounts to about 40% and is highly significant, but this advantage does not apply always to everybody: the factor of magnification of potential IV covers the range from one to two. The average increase of 66% at potential V is weakly significant for the intensity of 90 dB SPL. As expected from the results of contralateral stimulation the registrations at patients suffering from unilateral hearing impairment show on both sides the potential's threshold of the better hearing ear when stimulating binaurally; therefore you cannot determine the better cochlea. In addition to this fact the binaural stimulation of patients suffering from an acoustic neuroma removes the diagnostically important tool to recognize differences between the two sides. These findings are demonstrated by examples. Since it is impossible to predict an increase of the amplitude in the individual case and since there are serious diagnostic disadvantages, we don't deem advisable a binaural stimulation.