Auditory Brainstem and Middle Latency Evoked Response Sensitivity near Threshold

Abstract

Auditory brainstem response (ABR) and middle latency evoked response (MLER) testing have been used successfully for assessing hearing sensitivity electrophysiologically. Though both procedures have their proponents, ABR seems to be the more popular of the two. However, this study shows that overall, MLER waves occur with greater frequency at low sensation levels than ABR waves. Specifically, MLER wave Pa was the most sensitive wave, followed by ABR wave V, MLER wave Pb, ABR wave III, MLER wave Pc, and ABR wave I. Latencies were more consistent and predictable for ABR than MLER. However, as expected, amplitudes for MLER waves were greater than those for ABR. Given these results, those involved in measuring hearing sensitivity electrophysiologically are encouraged to consider the potential of the MLER measure and not limit their scope of assessment to ABR.