Residual noise estimation and Fsp: Strategies for optimizing Evoked Potentials recordings

Signal averaging is particularly crucial in evoked potentials where signal to noise ratio is very poor. This is the only manner to extract physiological data from noisy recordings. Various number of sweeps may be averaged depending on the test type: from 200 sweeps in VEP up to 5000 sweeps in AEP. It is usually up to the technician performing the test to decide when a recording shall be considered of good quality, by visually assessing the baseline stability and prominence of the physiological response. Stopping the averaging process is thus a subjective decision made by the technician. One way to support the operators is to provide quantitative data related to the quality of recording.