Effect of axon diameter and electrode position on responses to sinusoidally amplitude-modulated electric pulse-train stimuli

Purpose Cochlear implant systems restore the sense of sound by stimulating auditory nerve fibers (ANFs) with surgically implanted electrodes. Neural activity elicited by electrical pulse-trains conveys sound information to the brain. Thus, it is important to understand how ANFs produce the temporal sequence of neural activity in response to sinusoidally amplitude-modulated (SAM) pulse-trains with a rate of 5,000 pulses/s. In this study, we evaluated the effects of axon diameter (1.2 to 4.6 μm) and the electrode-to-axon distance (0.525 to 1.00 mm) on the response to 100 Hz SAM pulse-trains using a computational ANF model.