Loudness summation study on multielectrode pair stimulation Free

This psychophysical study investigated loudness summation for the activation of two, three, or four electrode pairs in a stimulus period. The electrode pairs were activated in temporally nonoverlapping manner. Two multichannel cochlear implant patients participated in the study. The method of magnitude estimation was used. Loudness growth for each electrode pair was first determined. The loudnesses of each electrode pair in a multielectrode pair stimulus were always set equally loud. The results showed that: (a) loudness increased with current level and the number of electrode pairs within a stimulus; (b) loudness summation for stimuli containing two electrode pairs was complete when the electrode pairs were approximately four electrodes apart (3.00 mm); and (c) loudness summation for stimuli containing three or four electrode pairs was incomplete in comparison to the results obtained for stimuli containing two electrode pairs. [Work supported by NIH Contract NOI‐NS‐9‐2400 and NIH Grant NS21027.]