Amplitude- and latency-growth functions of human electrocochleographic and brainstem responses

Early auditory evoked potentials (AEPs) are widely used in research and clinical practice, yet existing datasets often show substantial variability and limited age control, reducing their diagnostic value. To address this, this study simultaneously recorded compound action potentials (CAPs) and auditory brainstem responses (ABRs) in young, normal-hearing adults using both clicks and level-specific chirps. Amplitude- and latency-growth functions revealed robust, level-dependent differences between peripheral and brainstem responses, with chirps producing larger amplitudes and improved peak detectability. The study further evaluated a modeling framework in which simulated auditory nerve responses were convolved with individualized unitary responses to predict AEP waveforms. The model reproduced key CAP and ABR features-particularly at higher intensities-but showed systematic deviations at lower levels. Overall, the results support the utility of a linear convolution approach for linking cochlear and brainstem responses under normal-hearing conditions. While this dataset provides a rigorously controlled reference, larger cohorts will be needed to fully capture inter-individual variability. By integrating high-quality physiological measurements with computational modeling, this work lays the foundation for individualized diagnostics and advances a mechanistic understanding of early auditory processing.