I got my 1st Shingrix shot a week and a half ago. (I was called by a pharmacy whose waiting list I had been on for 7 months.) The next morning, it felt like there was pressure inside my left ear, I had a headache, and I had strange noise in my ear (tinnitus). This continued over the next 2 days. The next morning, I woke up and realized that I was completely deaf in my left ear.
I searched on my insurer's website for an ENT doctor, and began calling all of them at 8am. I got very lucky. On my 2nd call, the doctor himself answered the phone. I explained what was happening and he told me he could see me 3 hours later. (Turns out he is semi-FIRE'd.) He examined me and said there was no fluid in my ear, nor was there a wax buildup. He gave me a hearing test. The only sounds my left ear could hear were extremely high-pitched tones. My right ear had normal hearing.
He put me on an 11 day steroid course, as well as an antibiotic as a prophylactic, 2 different over-the-counter decongestant meds (though I wasn't congested), and a baby aspirin to prevent a microclot, he explained.
48 hours later, my hearing began to return, though it was degraded, and the tinnitus was still present. My hearing seemed to improve quite a bit over the next 24 hours but the tinnitus has remained. I saw the ENT again after my hearing began to return. After I complete the steroid course, he's having me get a full audiometry with an audiologist, then I'll return to see him. He mentioned in my 2nd visit that when a sudden hearing loss occurs but the loss is not 100%, that steroids are often effective in restoring hearing. He also urged me to take Melatonin before going to bed. A double-blind study indicated that it is often helpful with tinnitus.
A close friend who is an M.D. (and who recently FIRE'd) has been very helpful. She confirmed that the steroid course seemed to be the standard treatment for my situation. She did a fair bit of research and she believes that my hearing issues are indeed a reaction to the Shingrix shot. I think that, too. We have both read a handful of similar accounts. My ENT, however, thinks it is unlikely to be related to Shingrix. (If not, that would be quite a coincidence for someone who has never had any hearing issues.) However, he said that he doesn't plan to get the Shingrix vaccine himself.
I have decided that I will not get the 2nd Shingrix shot, and my doctor friend now thinks that she won't get the shots, either.
FWIW, I don't have any known underlying health issues and wasn't on any medication. I've never had shingles.