AEP variables will include individual amplitudes of N100 and P200 responses and the derived peak-to-peak amplitude of these responses (N100-P200) in microvolts (µV).

MMN is a response to nonmatching sounds in a series of matching sounds. Two tones of the same frequency and sound intensity, but differing in duration, will be sequentially presented to the participant through insert earphones. MMN amplitude will be measured from the peak of a mid-latency negative voltage deflection in the difference waveform representing the response to deviant stimuli in µV.

ASSR is used to assess the integrity of sensory pathways including cortical processing. ASSR will be measured at midline central electrode (Cz) of electroencephalogram (EEG) to assess the response in hertz (Hz). In ASSR, streams of "click" stimuli will be presented at a rate of 40 Hz while the participant will be instructed to fix their gaze on a white cross displayed on a computer monitor.

Improvement of the P300 auditory response time in milliseconds using P300 AEP in a target detection paradigm by an increase in amplitude and/or a decrease in latency will be analyzed. In this paradigm, 2 tones of the same sound intensity, but differing in frequency, are sequentially presented to the participant through insert earphones. The "standard" (low frequency) stimuli will be presented on the majority of trials, with a "target" (high frequency) stimuli presented periodically at random. The participant is told to listen for the "target" stimuli and press a button on the handset as fast as they can. The endpoint variables of P300 amplitude and latency in correlation with the button press reaction time will be used to assess the response time.