Free field frequency discrimination abilities of cochlear implant users

Poor music perception abilities of cochlear implant users may be attributed to limited pitch resolution afforded by the implant system. We investigated (i) what the typical frequency discrimination thresholds of cochlear implant users would be in free field listening conditions and (ii) whether frequency discrimination behaviour would be influenced by the position of the reference frequency relative to the frequency response of filters selected from the user's map. Frequency discrimination thresholds were determined according to an adaptive two-alternative forced choice (2AFC) method, using pure tones delivered in free field conditions. Results showed that finer frequency resolution than previously thought could be available to cochlear implant users. Results are interpreted in terms of intermediate pitch percepts possibly created by near-simultaneous activation of adjacent electrodes, resulting in overlapping neural populations to be stimulated. The findings may contribute to strategies aiming to improve music perception abilities of cochlear implant users.