Measurement of signal and noise characteristics in ongoing auditory brainstem response averaging.

Although diagnostic testing with auditory evoked potentials (EPs) has become routine, quantitative measurements of signal and noise are still lacking. In this study, current signal, power, noise power, and signal-to-noise ratio (SNR) estimation formulas are reviewed and applied to auditory brainstem response averaging. Single-sweep responses to individual sound stimuli are recorded and estimation formulas are evaluated during off-line averaging under various sound level and noise conditions. The results show that the quality of the averaged EP can be quantitatively assessed by the continuous display of the SNR and residual noise estimates during the averaging process. This method also allows the study of different types of averaging techniques to improve EP response acquisition.