Some Improvements in the Measurement of Variable Latency Acoustically Evoked Potentials in Human EEG

Since averaging of acoustically evoked potentials of variable latency yields inconsistent estimates, we tried to improve the results by applying Woody´s adaptive filter [8], a weli-known template-cross-correlation method. However, the results were worse and obviously less reliable than those reported by Woody. The following reasons for this behavior were found: 1) low signal-to-noise ratio and 2) large coincidences in the spectral components of EEG and of acoustically evoked potentials, enabling erroneous synchronizations of evoked potential-like EEG transients.