Clarification

Due to numerous requests to explain the Psak of Mori V'rabi Harav Hagaon R.Shlomo Miller Shlita.

The Halachic difference between hearing aids & cochlear implants is that hearing aids amplifies the sound which is heard through the ear.
Cochlear implants bypass the ear canal, they don't hear through the ear. It is as if someone were to tap them and they understand what is being communicated to them. It is not considered hearing.
Therefore the rule of שומע כעונה won't apply.