Hi Raimund,
Changes in your tinnitus are to be expected in the beginning! I am undergoing hypersensitivity treatment. Long story but I began to sleep with earplugs and my brain latched on to the closest sound it could find - the tinnitus. It happened slowly (over a decade) so when I finally went to an ENT it took many tests to determine that I had both tinnitus and hypersensitivity. Trust me - hypersensitivity is worse than tinnitus.
The first step was to treat the hypersensitivity. After about 2 months I noticed times I would not be clenching my jaw so bad. I slept better but the ringing was not only becoming louder; it was changing.
My doctor said that was normal. By month 4 my tinnitus kind of took the forefront. My hearing was now able to handle normal sounds and I wasn't in pain when I walked into a StarBucks. The tinnitus was now becoming the harder part to cope with for the first time since I was a kid.
We are 8 months into therapy and I am going back soon to begin easing off the hypersensitivity treatment and begin the tinnitus treatment. Unfortunately, it's only masking treatment. Not relief treatment.
As long as the decibels are not too loud you will discover changes. It's normal. Keep noise going at all times. Rain, white noise, fans, etc. When doing therapy, limit the volume and try not to think about it. I always stay within 20db-50db and only go 50db when I am outside.
Do whatever you can not to focus on the tinnitus hz. As hard as it is, ignore it. Once you find an ACRN, set it and go. No playing with hz or frequencies. Jot the frequencies down so you don't spend time trying to program the app. The more you can just set it and go, the better you will be. Trying to match your tinnitus with settings actually causes your brain to tune in more. That will be counterproductive. Set and go. Remember that.
You're in this for the long haul. There is no quick fix but you have hope and hope is powerful.
j