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 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 1-D nonlinear cochlear transmission-line model designed for the human auditory periphery 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 frequency range - were adjusted to match each species' auditory periphery and hearing range. Other cochlear parameters were calibrated to reproduce realistic cochlear tuning and compression. The adapted mouse and gerbil models were validated against experimental BM velocity level-growth characteristics, auditory-nerve (AN) tuning curves, and 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 cochlear synaptopathy reproduced observed differences in recorded auditory brainstem and envelope following responses from mice and gerbils with SNHL. OHC individualization of the mouse model based on DPOAEs failed to faithfully reproduce individual measurements, although intergroup differences in OHC damage were captured. Our findings demonstrate that biophysically grounded auditory models can be translated across species while preserving realistic sound-coding properties and pathophysiological alterations.