Auditory Brainstem Responses in Modern Audiology

Auditory Brainstem Responses in Modern Audiology: Clinical Utility, Advanced Paradigms, and Perspectives as Biomarkers of Cochlear Synaptopathy and Normoacusic Tinnitus

Auditory brainstem responses (ABRs) are short-latency evoked potentials reflecting the synchronous activity of the peripheral auditory nerve and brainstem pathways.

Traditionally used for objective threshold estimation and retrocochlear diagnostics, ABRs are experiencing renewed interest due to advanced stimulation paradigms (e.g., paired-click), expansion toward complex stimuli (speechevoked ABR), and the adoption of automated and artificial intelligence-based waveform analysis. In parallel, a growing body of literature has proposed ABR metrics - particularly wave I amplitude and wave V/I ratio - as indirect markers of cochlear synaptopathy (“hidden hearing loss”) and central gain compensation, especially in individuals with tinnitus and normal audiometric thresholds.

However, the large inter-individual variability of amplitude measures and the lack of consistent findings across studies require cautious interpretation. In these contexts, ABR should be considered a supportive tool to be integrated with complementary measures such as wideband middle ear muscle reflexes, speech-in-noise testing, otoacoustic emissions, and extended high-frequency audiometry.

This review summarizes established clinical applications, methodological considerations, emerging paradigms, and the current evidence for ABR as a potential biomarker Beyond threshold estimation.