My two cents (maybe more),
My onset was 9 weeks ago and 5-6 days after the onset the ringing was gone to 0. It stayed like this for 2 weeks. And then i woke up with a different (lower freq) ringing in my right ear. After 1 week i went away as well. I enjoyed 0T for 3-4 days and after that i woke up with higher freq ringing in my both ears. It's still here and i guess here for good.
My guess is, the hearing is not a continuous function and there is some sort of a hearing threshold. If any impulse created by the ear is below the threshold, it's not registered as sound and you do not hear anything. If it exceeds the threshold, then you start hearing them. The brain increasing the gain because of no communication with ear for some particular frequencies is the major cause of T a we know.
I also think that this threshold is not stationary. It may be represented as a graph wrt frequencies. In normal people who has no T and/or H this threshold is fairly stable and linear. Whereas, for us it may be not linear and show some sharp down/up spikes. I tend to correlate these with Loudness Discomfort Level (LDL). For example, my LDL values are ~80 db for 1KHz and 4 KHz which is a clear indication of H.
So if i connect this hypothesis with my experience i can conclude as;
1. The times where i heard absolutely no T, the ringing was below the hearing threshold.
2. The increase/decrease of ringing after the onset is because of the hear/brain to find a stable new level for the hearing threshold. After some trials, the ear/brain decided to lower the threshold to be able to hear more of the damaged frequencies. The lower hearing threshold also means i'm more sensitive to any sound around these frequencies, hence H.
I hope, over time the threshold shall go up slowly as my hearing loss and the traumatic conditions diminishes. H becoming more manageable is not something rare AFAIK. To monitor these, i'm planning to have the followings periodically, like 2 every year;
1. Audiogram: Shows up nothing, if i believe this i have no hearing loss
2. Otoacoustic Emissions: Much more sensitive test, shows up ~25db the loss bw 6.7-9.5 KHz.
3. LDL: ~80db. Normal should be able to bear 120db for short time and sustain ~100 for 1 hour
Umut