Computational Auditory Periphery Models: the Return of the Rodent

Animal experiments have provided many insights on auditory function, notably in cases of sensorineural hearing loss (SNHL). However, it is not always clear how these findings translate to the human auditory system, especially in clinically relevant contexts. Cross-species computational models of the auditory periphery can help bridge the gap between non-invasive human diagnostics and experimental evidence from animal studies. In this work we adapted a one-dimensional (1-D) nonlinear cochlear transmission-line (TL) model designed for the human auditory periphery (Verhulst et al., 2018) to mouse and gerbil, enabling a single computational framework for cross-species research on SNHL. Species-specific anatomical and physiological parameters - including basilar membrane (BM) length and width, stapes area, middle-ear transfer functions, and characteristic-frequency range - were adjusted to match each species' auditory periphery and hearing range. Other cochlear parameters were calibrated to reproduce realistic cochlear tuning and compressive growth. The adapted mouse and gerbil models were validated against experimental species-specific BM velocity level-growth characteristics, auditory-nerve (AN) tuning curves, and distortion-product otoacoustic emissions (DPOAEs). Simulated AN outputs reasonably matched empirical measurements, including realistic AN thresholds and frequency selectivity. However, the discrepancy between simulations and measurements became larger for cochlear sections closer to the base or apex. Simulations of auditory nerve synaptopathy reproduced observed differences in recorded auditory brainstem and envelope following responses from mice and gerbils with cochlear synaptopathy. However, OHC individualization of the mouse model based on DPOAEs failed to faithfully reproduce individual measured data, although inter-group differences in OHC damage were captured. Our findings demonstrate that biophysically grounded auditory periphery models can be translated across species while preserving realistic sound-coding properties and pathophysiological alterations. This approach refines the interpretation of animal data in specific hypotheses of human hearing, facilitates the development of new stimuli to test in rodents, and may enable in silico investigations of OHC loss, synaptopathy, and their functional consequences.