New Tinnitus Sound After Spike Disappears After Plugging Ear with Thumb?

I've got some new acoustic trauma a week ago which I described here https://www.tinnitustalk.com/threads/spike-and-ear-fullness-after-noise-at-surgery-room.25903

As I wrote my tinnitus spiked in both ears, but it seems to fading to previous baseline. But the strange thing is that I got new constant sound in my right ear after this incident, that disappears when I plug my ear with my thumb. When it comes to wearing earplugs it varies, it's there once and then second time I can't hear it.

When I plug my ear with my thumb a think that sometimes I only hear sound that was in my previous baseline, and sometimes this new sound. It's changing but today after plugging with thumb I only hear previous baseline.

I've always had this kind of sound in my right ear before recent incident and it was 90% maskable during the day. But it's very strange, i can't even properly explain it. It's different kind of sound, it's low/medium squeek like in radiatior.

So to put it in one sentence, I hear new sound when I don't plug my ear with a thumb and it disappears when I plug it with a thumb. Ear was checked by the ENT, it's ok.

Before the incident i often got "vibrating" sensation like in TTTS in this ear, maybe it's it and it changed sound?

I'm still on the course of Prednisone 50mg/day and vitamins, magnesium, vinpocetine etc. NAC should come today.

I think about trying HBOT's but it's very expensive and loud, it should help me or it's only a waste of money and treatment above should be sufficient? I'm also gonna do extended audiogram today.

 

Update: Audiogram

Up: Right Ear
Down: Left Ear

We can see a drop on the left ear at 17KHz, right ear should be TTTS i think.

My left ear is a little louder than before the incident, could this be the cause? Should i consider HBOT?