What should be implemented in future cochlear implants?

Cochlear-implant performance can be improved by focusing on: 1) psychophysical studies to determine hearing limitations; 2) speech perception to suggest the most effective speech-processing strategies; 3) aural rehabilitation to effectively train patients to use the new electrical stimuli. Basic psychophysical studies have shown only weak correlations with speech perception. Perhaps more speech-like stimuli should be explored in psychophysical tasks. Studies on vowel and consonant recognition suggest enhancing all speech features, but particularly frication and place of articulation should help most patients. Probably the feature that would be the most beneficial to enhance is place of articulation, which is poorly coded even in the best patients. Empirical studies are needed to determine the ways in which these cues can be enhanced. Certain types of auditory training are likely to be beneficial, particularly when the signal is new, incomplete or distorted. However, much more research in aural rehabilitation is needed.