Interesting you should point that out because I have just realized I no longer have this!
Prior to IBT I had tinnitus on and off for years. Not a month would go by without my having a terribly irritating high pitched sound that seemed to be somewhere deep inside my head, and that is very difficult to explain to someone who has never experienced that.
Anyhow, I have not had this for at least a year and so that is another issue on the list that has resolved or improved...its a reoccurring theme that happens with things like IBT, in that you find out many weeks or months down the line that one of your ailments has vanished, and you never attribute it to IBT at all....In all honesty though I have been doing that many different things over the last couple of years that IBT may not have played a role in this particular improvement at all, but its a possibility, and I will never sleep flat again just in case.
Took me 2 year to realize I no longer have tinnitus hahah!