In my case, I went to bed with silence, and woke up in the middle of the night to loud T, which had stayed pretty much the same since (even the pre vs post surgery wasn't that different). I wasn't stressed, or anything - totally normal day/night. It would have been intuitive to me that, unless you had a trauma, it would maybe set in progressively, but somehow it came in one shot for me. Maybe my "special" otosclerosis did the equivalent of a trauma to my inner ear and broke something brutally. It is after all odd that otosclerosis would build up a 40 dB air-bone gap in 8 weeks only - it's supposed to take years/decades, but for me something happened very rapidly. What about you? Progressive? In one shot?