I have to take issue with this overly simplistic view of the situation. Now sure, your audiologist may have ‘dumbed it down’ for a patient, but I don’t really accept that this is true.
For starters, a really thorough hearing test considers results at 250Hz, 500Hz, 750Hz, 1000Hz, 1500Hz, 2000Hz, 3000Hz, 4000Hz, 6000Hz and 8000Hz. That’s 10 different frequencies. If it were truly critical to a good fit to alter the frequency output at 16 frequencies, wouldn’t a test typically include a test of 16 different frequencies?
Next, we need to consider the issue of bands. These split the channels down further to provide more fine tuning.
Finally, at least for this answer, we need to consider how adjustable each channel is. If you get a 16 channel aid and adjusting one channel affects maybe 1-4 other channels when making adjustments, then you don’t truly have the flexibility of certain other aids. You also need to consider what adjustments can be made with each channel, along with a massive variety of other factors.
To put it in other terms; can you state unequivocally, that a eight cylinder engine is ALWAYS better than a six cylinder engine? Is American NTSC television that updates 60 frames per second superior to European PAL television that updates 50 frames per second?
There is so much more to a hearing aid than how many channels it has.