Dual-electrode pitch discrimination with sequential interleaved stimulation by cochlear implant users

Cochlear implant users may perceive intermediate place-pitches between those elicited by the individual electrodes when two electrodes are stimulated simultaneously or sequentially. This study examined pitch discrimination between adjacent electrodes using sequential dual-electrode stimulation in terms of the sensitivity index, d', which was obtained by adding d's from intermediate dual-electrode stimuli. Loudness was balanced for each tested pair and the intensities were roved. Twelve ears with the Nucleus 24 or Freedom implants demonstrated a wide range of d', from 0.7 to 9.6. "Virtual channels" can be implemented through nonsimultaneous stimulation, with comparable pitch discrimination to that observed with simultaneous stimulation.