please consider putting your dog onto the BARF diet, before making any radical decision about surgery. Although I dont currently own a cocker, I did have a labrador for years with extreme ear problems, resulting in surgery. She has long since passed to the Bridge of old age, but recent discussions with my vet, who is now, very-Pro BARF have uncovered the possibility that had we known at the time, changing her over to BARF may have cured the problem without need for surgery!
I'm sure there are people on here who could tell you some amazing stories of health (and even behaviour) problems "gone away" with the advent of introducing their pets to BARF - I've seen some pretty amazing cures myself......
Must be worth a bit of time researching??
Incidentally, Holly our lab, got on fine after the op, and she still seemed to have some miniscule residual "hearing" due to vibration, hand signals and 6th sense i think,
although she was thereafter never off the lead anywhere near a road!