Cochlear implants are one of the dramatic success stories of the bioengineering enterprise. Although these prostheses are used extensively, they still can be improved substantially. We suggest that high-density electrode designs will permit field shaping and field steering to an extent not presently possible with the arrays that are used today. Those opportunities will make it possible to make use of the phase information that is richly available to normal listeners. Although this information makes possible more precise location of sound sources in the auditory environment, and will likely improve the recognition of intelligent sound in noise, it will require the consumption of additional power in future cochlear prostheses. Those opportunities and trade-offs provide the designers of cochlear implants with exciting goals for the future.
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