Direct in vivo measurement of cochlear place coding in humans.

Although tonotopic place-coding in the cochlea has been extensively studied, our understanding of how the human cochlea responds in vivo to acoustic stimuli remains limited. We recorded acoustically-evoked intracochlear responses from 50 human subjects using a cochlear implant electrode and constructed an electrophysiology-based map using postoperative imaging to locate each electrode contact. The basal shifted frequency-place map resulting from higher stimulation more closely aligns with everyday speech levels.