I just confirmed that, per your experience, on my car the sound gets louder when I switch the lights from "auto" to "park". However, I can still hear it when the car is in "auto" mode. Oddly, it in some ways gets more annoying when it's quieter. (Again I have tinnitus at about the same frequency, so it's particularly irritating; and as a result of sitting in my car for five minutes my ears ring extra loud for the next hour.)
i second that with the tinnitus. my tinnitus is about the same frequency of the car (i wonder if we developed tinnitus because of some kind of electronics if they resonate at those frequencies?). if they can't fix it, i cannot drive it as it is. it hurts my ears, its unsafe for me to drive it with that kind of aggravation of tinnitus. my car is still at the service center.