Yeah so I had an audiogram done in July and all frequencies were between 0 & 10 dB. A few months later another test showed a dip from 4-8 khz - all frequencies below 15 dB, with the biggest dip at 4 kHz being 35 dB.
I had no significant noise trauma which is the most scary part.
Yeah that is exactly where a 'noise notch' appears after years of abuse, not suddenly.
This is strange.
It's quite possible you've always had it or it was an incorrect audiogram. Not sure how else that could happen, either way if it was hearing loss, fullness could still fade as it's usually correlated with the initial cause, not the hearing loss itself.
Re: this 4-8 kHz dip suddenly appearing, this exact scenario happened with me, but it turned out to be the audiologist added a 25 dB noise notch at 4-6 kHz in one ear that wasn't there. I don't know if their intention was to sell a product or they were lazy, but ultimately they were wrong.
I had 3 other audiograms at different locations that ear was at 0 dB - 5 dB across that range. Like you, I was obviously confused and upset when I found out, but quickly learned it was false.
In your case, it is also possible that with the first test you had, the audiologist was lazy and kinda skipped over the bad ear after seeing the first was good. Thus the 2nd audiogram discovered the truth.
Have you had a second opinion?
I've never seen someone getting a sudden noise notch over a short period without an explosion or acoustic trauma (usually temporary hearing loss). You can obviously get other types of hearing loss suddenly, but a noise notch is very specific.
Someone correct me if I'm wrong.