[Evaluation of binaural interaction by the characteristics of short-latency auditory evoked potentials in guinea pigs].

Binaural interaction was evaluated by determination of the curve of difference between the algebraic sum of brainstem evoked potentials which had been registered under monaural stimulation of right and left ear and potentials which had been registered under binaural stimulation. The curve of difference is characterized by three peaks: N1, P1, N2 with peak latency IV-IV' without any masking noise, and during masking with the signal-to-noise ratio of +20-0 dB additional peaks N0P0 are registered in III-III' latency regions on the difference curve. With an increase of the sound pressure level from 47 to 107 dB the P1N2 amplitude grows and relation of the P1N2 amplitude to wave amplitude IV of the sum of potentials registered during monaural right and left ear stimulation remains constant. Under masking conditions the above relation increases with worsening of the signal-to-noise ratio and the P1N2 amplitude decreases. Binaural interaction pattern is not supposed to alter with an increase in the click intensity level, and during masking with the signal-to-noise ratio of +20-0 dB specific features of neurophysiological mechanisms of binaural interaction are observed.