I'm sorry to hear that @Hamsti . Prednisone is a bit of rolling the dice in terms of mitigating tinnitus. Have you tried supplements? NAC and Magnesium might help in the early stage of new tinnitus tones
Tinnitus Talk Support Forum
I also had a situation in which I got a new tone. It happened after an audiogram test. I quickly took some NAC, Theracurmin and Magnesium Threonate and the new sound went away quickly thereafter
It's not a sure thing, but anti-inflammatory supplements might be your best bet if new tinnitus tones are in the acute phase
BTW nicotinamide riboside might also be an option if you have a good drugstore in your close environment
Thanks for your support @Christiaan. Magnesium I take everyday. NAC I got at home, but I was afraid of taking it because of the known side effects. Maybe I should calm down and go for a long walk tommorow, to lower my cholesterol levels...and google nicotinamide riboside :)
Prednisoline very rarely causes or worsens hearing problems. In all likelihood, it's causing a temporary spike. As @Christiaan said, nicotinamide riboside is a real deal supplement -- it is expensive though. Another nice one is magnesium with zinc. All of these can help reduce nerve excitability, which is often a major factor when it comes to acute tinnitus.