Late auditory evoked potential: influence of stimuli intensity and auditory attention

The goal of the research presented here is the evaluation of the variation of LAEP waveform characteristics due to the stimulus intensity and the auditory attention. The experimental procedure combine three stimuli intensities and two cognitive tasks. A group of rules were proposed and an algorithm implemented in order to identify automatically the components P1, N1 and P2 and to determine their latency and amplitude values. At all, 72 LAEP registers were processed and analyzed and their mean values (s.d.) were computed. It was found significant reduction in P2 latency and significant increment in amplitude N1-P2 with increment of auditory attention. There is not relevant PEALL variation with stimuli intensity for stimuli levels below of 60 dB HL. Small variability is found for condition of more auditory attention and for the intensity of 70 dB HL.