Speech-evoked auditory event-related potentials (ERPs) provide insight into the neural mechanisms underlying speech processing. For this reason, ERPs are of great value to hearing scientists and audiologists. This article will provide an overview of ERPs frequently used to examine the processing of speech and other sound stimuli. These ERPs include the P1-N1-P2 complex, acoustic change complex, mismatch negativity, and P3 responses. In addition, we focus on the application of these speech-evoked potentials for the assessment of (1) the effects of hearing loss on the neural encoding of speech allowing for behavioral detection and discrimination; (2) improvements in the neural processing of speech with amplification (hearing aids, cochlear implants); and (3) the impact of auditory training on the neural processing of speech. Studies in these three areas are reviewed and implications for audiologists are discussed.

These results suggest that hearing-impaired individuals' brains process speech stimuli with greater accuracy and in a more effective manner when these individuals use their personal hearing aids. This is especially true at the lower stimulus intensity. The effects of sensorineural hearing loss and personal hearing aids on cortical ERPs and behavioral measures of discrimination are dependent on the degree of sensorineural loss, the intensity of the stimuli, and the level of cortical auditory processing that the response measure is assessing. The possible clinical significance of these cortical ERP and behavioral findings is discussed.

Most researchers agree that, in the future, ASSR testing will play an important role in clinical audiology. Therefore, it is important for clinical audiologists and Au.D. students to have a good basic understanding of the technical concepts associated with the ASSR, a knowledge of optimal stimulus and recording parameters used to accurately record this response, and an appreciation of the current role and/or limitations of using the ASSR to estimate behavioral thresholds in infants with various degrees and configurations of hearing loss.