Great post. The cognitive mechanics you're describing ties in with one of the hot topics in theory of consciousness research, namely "global workspace theory".
http://en.wikipedia.org/wiki/Global_Workspace_Theory.
The conscious mind has to deal with a host of signals from the unconscious mind every second of the day.
Think of your conscious mind as being an enormous cave in pitch blackness. The cave is your global workspace.
Inside the cave is you; or to put it more simply your attention. The "you" carries a flashlight and constantly sweeps it across the cave illuminating all these signals one by one as they're in little alcoves like you see in crypts in horror movies.
Some of the alcoves have little doors on them that you have to open to see what's inside: they're your memories.
The rest are filled with concurrent signals from your senses and unconscious mind. "whats in this alcove? ah yes that's the signal from my olfactory system (a smell) . "What's in this one? ah yes the the sensation of my forearm on the table" As the flashlight sweeps across the cave it illuminates alcove after alcove as you direct it across the walls of the cave.
So; you're in a dark cave. Your looking in the alcoves, then all of a sudden...you hear a noise! What's the first thing you do?
Exactly.
You swing your flashlight (attention) around straight away to find out what the hell it is. The noise is the emotion your limbic brain ascribes to the signals in your alcoves. The bigger the emotion the louder the noise, the louder the noise the more attention you give it. It's your minds way of making you pay attention to things which are important to you. That's what emotions do.
Suppose you're crossing the road in a busy city with lots of people? No big deal, lots of noises coming in from all around you, then all of a sudden...a car horn. Boom, the alcove emits a loud noise, you spin round to see what it is, see it's Dr Nagler trying to run you down for wearing a pro LLLT t-shirt and straight away you leap out of the way of his Ferrari and you're saved. Relief!!!
The car horn was just another sound in the background, but... you paid attention to it as you're unconscious mind recognised it as being dangerous and made you pay attention to it.
Now tinnitus is a signal which sits in it's little alcove. How much emotional relevance would you want to give it if you didn't want to hear it? You see where I'm going with this...
Well we can't just flick a switch and turn it off, It's process which takes time (which is of course; Habituation.)
This is where IWLM's method comes in. Fortunately there is a feedback system from the conscious mind to the limbic system (which is why affirmations work) and IWLM's method uses this neural pathway to perform it's magic. Remember that these limbic system signals which attach to your sensory inputs are to attract your attention. Well, by acknowledging to your limbic brain that you're receiving the signal it's sending, and doing so in a "how you're feeling" about it way, then you're using the limbic systems own language to communicate with it; the language of emotion. You're saying "got you loud and clear; over and out" the limbic system has performed it's evolutionary remit and got a response from your conscious mind that the signal (your tinnitus) has been examined and found to be a false alarm. The flashlight swing on to the next nosiest thing.
Wonderful thing the brain.