@Baltazard (post edit to the succeeding post just below me) → I’ve noticed from this forum that many folks with moderately severe hearing loss in the lower frequencies to severe to profound hearing loss in the high frequencies don’t tend to do well with Oticon and find the Phonak aids much better suited for them.
I’m just guessing here that the heavier hearing loss limits the wide dynamic operating range rather severely, and with a much narrower dynamic range, there’s simply not enough room for nuances for the open paradigm to work as effectively. You end up having too many sounds in play due to the open paradigm, competing with each other in a much narrower dynamic range, and things tend become a cacophony that’s nearly impossible to sort out. The Phonak more aggressively isolates out the noise and give more weight to the speech, which nicely eliminates and alleviates the competition between too many sounds.