This has been highly-variable for me over the years. I have noticed changes with with caffeine intake and exercise. On many occasions I've felt my ears "pop" a

This has been highly-variable for me over the years. I have noticed changes with with caffeine intake and exercise. On many occasions I've felt my ears "pop" after an extensive cardio session. The result feels like I just took really weak earplugs out. Rowing is more prone to do this than other forms of exercise in my experience. I've also noticed that if I force myself to sit in total silence and remain as calm as possible, whatever ringing I can hear will start to diminish to ~imperceptible within a few minutes. When I'm on edge and anxious, the opposite appears to be true.