Speech-evoked auditory brainstem response as a biomarker of auditory plasticity: clinical and neurophysiological perspectives — a narrative review

Abstract Background The speech-evoked auditory brainstem response (s-ABR) is an objective electrophysiological measure that captures how the brainstem encodes the temporal and spectral features of complex acoustic signals. Unlike conventional click-evoked ABR, which primarily assesses neural synchrony to brief broadband stimuli, s-ABR tracks the ongoing neural representation of speech sounds at the subcortical level, offering a window into auditory processing that behavioral tests alone cannot provide. Main body Over roughly two decades of research, s-ABR has shown sensitivity to subtle differences in neural timing across a diverse range of populations. Altered brainstem encoding has been described in children with auditory processing disorder, dyslexia, and attention-deficit/hyperactivity disorder, as well as in older adults experiencing difficulty with speech in noise. At the same time, enhanced subcortical responses have been reported in musicians, bilingual individuals, and those who have undergone structured auditory training — a pattern broadly interpreted as evidence of experience-dependent plasticity. In cochlear implant users, s-ABR may provide additional information about subcortical auditory function that complements standard audiological assessments. Conclusion Despite growing clinical interest, the routine use of s-ABR remains hampered by considerable variability in recording protocols, the absence of large normative databases, and susceptibility to myogenic and electromagnetic artifact. Standardization of acquisition parameters, expansion of reference data across linguistic and demographic groups, and validation of newer analysis approaches such as temporal response functions will be necessary steps before s-ABR can be reliably incorporated into everyday clinical practice.