Input-output function and adaptation behaviour of the five early potentials registered with the earlobe-vertex pick-up

Abstract

At twenty-three 20-30-year-old normal-hearing subjects the characteristic curves of amplitudes and latencies of the five early potentials, appearing within the first 8 ms after stimulus onset, were obtained. The potentials were registered with the earlobe-vertex pick-up, as described by Sohmer and with click stumulus rates of 5/sec, 10/sec and 100/sec; It could be seen: All five potentials depend in amplitude and latency on intensity; all potentials show with increasing click rate an adaptation and a delayed latency, when increasing the click rate from 10/sec to 50/sec; the adaptation phenomenon of the 1st, 2nd, 3rd and 4th potential is the most prominent, the 4th potential shows the smallest adaptation effect; the characteristic curve at 10/sec of the 1st and 3rd potential demonstrates a break at 70 dB SPL; the latencies of the five potentials begin to increase at click rates higher than 10/sec; the 4th potential seems to be the most suitable one for measuring the acoustical threshold; only the fifth potential diminishes in amplitude and increases in latency after administration of an anaesthetic, but an additional relaxant does not alter it any more.

Neural responses to auditory temporal patterns

“…Typically, changes in the rate of presentation generally result in changes of both amplitude and latency of the auditory brain-stem response in humans (Pratt and Somner, 1976;Zollner et al, 1976). We did see some changes in the absolute latency values associated with rate changes for responses, but these changes were small and not systematic.…”

Auditory brainstem and middle latency responses recorded at fast rates with randomized stimulation

“…This method has the limitation that the ISI must be greater than the averaging window to avoid contamination of the recording by the adjacent responses; otherwise it would not be mathematically possible to recover the overlapping AEP (Zollner et al, 1976;Kjaer, 1980;Jewett et al, 2004). Considering standard averaging windows of 10 ms for ABR signals and 100 ms for MLR signals, ABRs and MLRs cannot be recorded with the conventional method at rates higher than 100 and 10 Hz, respectively.…”

Recording of auditory brainstem response at high stimulation rates using randomized stimulation and averaging

“…This technique has the important limitation that the ISI must be greater than the averaging window in order to avoid the contamination of the recording by an adjacent response (e.g., Zollner et al, 1976;Kjaer, 1980). Therefore, the CONV technique cannot be used to record ABR at rates higher than 100 Hz.…”