Cochlear, brainstem, and psychophysical responses show spectrotemporal tradeoff in human auditory processing

Auditory filter theory posits a tradeoff in time-frequency analysis: high temporal precision is achievable only at the expense of poorer frequency resolution and vice versa. Here, we examined the hierarchy of brain mechanisms of these spectrotemporal tradeoffs through a series of physiological and behavioral measures aimed to tap temporal and spectral acuity at different levels of the auditory neuroaxis (cochlea→brainstem→percept). Cochlear and behavioral frequency selectivity was measured by stimulus-frequency otoacoustic emissions (SFOAE) and psychophysical tuning curves; temporal acuity was measured physiologically and behaviorally by paired click recovery of auditory brainstem responses (ABRs) and gap detection thresholds (GDTs), respectively. Comparison of physiological and behavioral estimates of temporal acuity and frequency tuning showed high consistency between measurement domains with temporal thresholds of ∼3-4 ms and filter tuning Q3≈10 across brain and behavioral measures. Cochlear SFOAE estimates of tuning inversely predicted listeners' temporal acuity estimated from both brainstem ABRs and behavioral GDTs. The high predictive power of cochlear responses on temporal thresholds and similarity between time-frequency tradeoffs measured at progressively higher levels of the processing hierarchy (brainstem, behavior) suggest that the temporal resolution of human hearing established in the cochlea might be inherited at progressively higher levels of the hearing pathway.