My Perspective: Auditory Evoked Potentials Using Speech

Abstract

Purpose: The purpose of this tutorial is to clarify the use of speech sounds as stimuli for auditory evoked potentials and how these might contribute to our understanding of speech, language, learning, and hearing disorders. Speech-evoked auditory brainstem responses (ABRs), auditory steady-state responses, auditory middle latency responses, mismatch negativity, P300, cortical onset responses, and the acoustic change complex are reviewed. Method: The author drew upon her scholarship in this area from over 4 decades of research and teaching to summarize the major findings when using speech stimuli to evoke auditory potentials that have been used in clinical contexts. Results: Speech-evoked auditory potentials contribute to our understanding of how the brain processes the acoustic features of speech sounds, providing information that is complementary to psychophysical tests. When psychophysical tests cannot be performed owing to neurodevelopmental immaturity or disability, or cognitive disability, speech-evoked auditory potentials may be used to estimate the benefit of amplification or implantation for speech, language, and hearing. Conclusions: The benefit of using auditory evoked potentials for evaluation is that they provide insight into the brain mechanisms underlying hearing and listening disorders that audiologists aim to treat. While we can use the known correlations between perceptual and electrophysiological responses for “cross-checking” our evaluation results, examining when discrepancies occur is also especially meaningful. For example, the complex ABR reveals subcortical issues in temporal processing that would not be evident in ABRs to clicks or tone bursts, nor in behavioral testing. P300 can document slower neural processing of speech stimuli that may be relevant to the rehabilitation of older adults, even when word recognition scores appear to be congruent with the pure-tone audiogram. In these ways, auditory evoked potentials for speech provide audiologists with tools for demonstrating to clients how their brain responds to speech and opening the conversation for rehabilitation.