Even a hearing aid with 64 channels will still have only up to about 15-16 handles or bands (to adjust amplification). I remember Dr. Cliff Olsen was reviewing some hearing aid model and a minus he pointed out was that it only has 10 handles as opposed to 15 handles, which is no huge deal, but still will limit the audi’s ability to fine tune the adjustment to a more detailed level.
Alhough users may not be able to tell the difference between a 64 channel hearing aid and a 12 channel hearing aid, strictly based on the channel difference, a higher # of channels still usually indicates a higher premium level of hearing aid compared to a 12 channel hearing aid.
The number of channels aid in the background processing for auditory analysis, feedback cancellation, noise reduction, etc. So while you may not benefit directly and be able to tell a difference, you’d still be able to benefit indirectly thanks to more sophisticated and complex signal processing and analysis, made more advanced thanks to a higher number of channels.