I don't have an acoustic neuroma but I can sure identify with a great deal of what people are describing here! I do seem to have some kind of retrocochlear problem, but they were never able to identify what it is. I had sudden deafness on my left side after sneezing hard in 1999. Just got a Baha implant July 24, getting the processor in two months!
About a month or six weeks after my sudden hearing loss, I began getting what at the time I called "brain blinks" for lack of a better word. I would suddenly get a split-second feeling that I was about to involuntarily close my eyes and conk out, accompanied by a sensation of "total dizziness" or "whump' in my head and also a "burst" of "extra" static in my bad ear (which had constant whirring tinnitus anyway).
These would happen spontaneously but much more often when I was sleepy or in the twilight between sleep and wake. Also they were triggered by a sudden sound (such as telephone ringing or someone coughing). Also triggered by the CESSATION of a staticky noise--I'd get the "whump" when I'd turn off running water or change the radio station.
Eventually the "whumps" became less strong (no more feeling like my eyes were going to close) and lasting maybe a second as opposed to half a second. I also noticed that they frequently occurred when moving my eyes left or right, sometimes up or down. I believe this is related to gaze-evoked tinnitus (Google it) which can occur after removal of acoustic neuroma. Some researchers in Buffalo did a study of gaze-evoked tinnitus in AN patients, published in 2001 I believe.
After 9 years, I get the "whumps" rarely now, and usually only in the sleep-wake twilight.
As for hearing "explosions" or other noises when falling asleep, Google "hypnagogic hallucinations". Apparently these things are common. I don't hear things, but I often wake up with a start 15 minutes after falling asleep, sometimes kicking my legs out, having dreamed (almost always) that I'm slipping on wet leaves!