Janie, to answer your questions, I had roughly 50 to 55 dB of hearing loss on my AN side in a narrow band ranging from 2 to 4 kHz, before CK treatment. Otherwise, the response on my left and right sides were about the same. At my first post-treatment hearing test, 5 months after CK, I had 15 dB additional hearing loss in the same band on my AN side. Subjectively, it doesn't seem like I've lost any more hearing since then (I'm now 10 months post-CK).
Before treatment, I had intermittent episodes of progressive hearing loss, always accompanied by sensations of fullness in the affected ear. My tinnitus was getting louder over time and was both "ringing" and "pulsatile" (specifically in my case, hearing my pulse in my ear) in nature. I also had constant disequilibrium. Several times each day, I felt like an "invisible hand" would push me so that I would start to fall over to one side while standing.
Since getting CK, my ringing tinnitus has been cut to about 1/3 the level it was before getting treatment and the pulsatile tinnitus immediately disappeared and has not come back since. (This is a very unusual benefit, and shouldn't be expected by anyone seeking radiation treatment.) The "invisible hand" stopped happening -- for the first time in over 8 years -- about six months post-CK. I still have constant but mild disequilibrium, but it doesn't stop me from being active; CK didn't improve that. I had, for about a week, fullness in the ear and hyperacusis (garbled, distorted hearing) on my AN side 4-1/2 months after CK, which is when it felt like I lost the other 15 dB of hearing (hearing hasn't come back but my hearing is no longer distorted).
It is important to realize two things about hearing loss vis-a-vis radiation treatments:
1. At your age, you are likely to have continued age-related hearing loss that might be confused with loss due to treatment. Be sure to see if any additional loss is bi-lateral or not. If it's bilateral (the same decibels of additional loss in both ears), then it's not a result of the AN or aging. Unless, of course, you have NF-2 (bi-lateral tumors).
2. As Dr. Chang said to me, additional loss after CK treatment cannot necessarily be concluded to be as a result of the treatment. As both your doctor and Kate pointed out, the tumor can continue to degrade hearing even if it stays the same size. And the AN does not immediately die when it's irradiated. It's a process that takes awhile -- the DNA is damaged by the radiation, ending the tumor's cell-division process. As each cell fails to replicate, it dies. This potentially explains why fast-growing tumors (those that go through cell division quicker than slow-growing tumors) seem to exhibit necrosis (tissue death) quicker than the norm. This was true of my fast-growing tumor; my 5-month MRI showed an unusually high degree of tumor necrosis. But I digress. The point I'm trying to make is that even after irradiation, a tumor may cause additional hearing loss before it dies. Was it the radiation or the tumor that caused me to lose an additional 15 dB? No one can say with certainty.
Before I got treatment, I wanted to stay in W&W mode as long as possible. I was afraid that CK (or any other treatment) would decease both my hearing and balance functions. Indeed, this is sometimes the case with radiation patients (degraded balance in the short term, degraded hearing in the long term). During the 8 months in between diagnosis and treatment, my hearing and balance both worsened. In hindsight, I now wish I had gone sooner into treatment (the right treatment -- which for me was CK -- and not just any treatment; making a decision on which type of treatment to get shouldn't be rushed, as it is potentially one of the most important decisions you'll make in your lifetime). I do believe that the less damage you have to cranial nerves before getting treatment, the better they will withstand the necessary trauma of treatment and will have better-preserved function afterwards.
Good luck in your journey, Janie. We're here to help, if you need it.
Best wishes,
Tumbleweed