抄録
In order to investigate the reliability of 40Hz event related potential (40Hz ERP) in audiometry, discrepancy between the 40Hz ERP and the behavioral threshold were compaired in normal adults, normal children, adults with hearing disorders and children with hearing disorders. Though 40Hz ERP measurements for adults were performed in awake state, the measurements in children were performed in asleep. For the acoustic stimuli, 0.5, 1 and 2kHz tone pips were given with repetition rate of 40/sec. A total of 1024 sweeps were averaged in each series with a window length of 50msec. For smoothing wave form, 80-120Hz bandpass analog filter and 20-80Hz bandpass digital filter by means of FFT algorithm were used.
The results were as follows;
(1) The mean differences between 40Hz ERP thresholds and behavioral thresholds were 0-30dB in adults and 10-50dB in children.
(2) The correlation coefficients between 40Hz ERP thresholds and behavioral thresholds in patients with hearing disorders were 0.77-0.8 in adults and 0.63-0.67 in children.
(3) These results shows that the 40Hz ERP is useful for hearing evaluation in adults, but test reliability is not enough for determining accurate hearing in children.
