I think this is what was responsible for my worsened condition thanks to the behind-the-seat speaker "enhancement" of the IMax theater I was in. Normal movies I can handle with earplugs but I will never go to that kind of theater again (hindsight is 20/20).A lot of people do not realize that the best earplugs or moulded types, will not stop tinnitus spiking if external sound is loud enough, because it can pass through the head/skull and be transferred to the inner ear by bone conduction. I suspect this is what has happened in your case. No hearing protection can stop this.