Pattern analysis of auditory-evoked EEG potentials.

A pattern analysis approach to the detection of auditory evoked potentials in the EEG is reported. Pattern aspects of individual post-stimulus responses have been examined first through their correlation coefficients using the suprathreshold average evoked potential as a reference pattern, and second by the ensemble distribution of phase values of Fourier spectral components, employed to characterise signal pattern. The correlation study indicated that suprathreshold stimuli act to increase the reference pattern similarity of individual records. Individual harmonic phase values are distributed approximately uniformly for unstimulated EEG, but were demonstrated to be increasingly aggregated for increasingly suprathreshold stimuli. It is proposed that a fully objective audiometric technique can be based on a phase-spectral technique.