| Popis: |
The Fourier analysis of evoked potentials has several advantages over averaging. Regan introduced a “zoom” technique that manipulates stimulus parameters during the analysis [Invest. Opthal. 12 669–679 (1973)]. Six subjects were tested using this technique to assess the effect of stimulus rate on the auditory evoked potentials. A 95‐dB peSPL tone with 4‐ms rise and fall times and a 2‐ms plateau was presented to the right ear at a rate that increased from 10 to 60 tones/s over 50 s. This analysis was carried out for four different frequencies of the tone: 500, 1000, 2000, and 4000 Hz. The amplitude and phase outputs from the Fourier analyzer were repetitively recorded during the sweep in stimulus rate and averaged over 32 sweeps. The maximum amplitudes of the steady‐state responses for the 500, 1000, 2000, and 4000 Hz tones occurred at rates of 40/s, 43/s, 44/s, and 46/s with amplitudes, of 1.42, 1.34, 1.30, and 1.11 μV, respectively. This technique may be used in “zooming” other parameters of interest suc... |
