have you got brain noise?

This is an attempt to find a common cause for "brain noise" or as some know as ringing in ear. It would be interesting to find what leads to this. What past activities, experiences, or occupation may have brought this on. If you have it, is it always heard or just when you lay down to sleep.
In my case:
- loud music listening & playing 43yrs or so
- machinist as an occupation 30yrs +
- fair diet or no diet
- sensativity to low frequency
- high pitch hiss is my noise
I guess what started this is my "brain noise" (bn) is not too bad yet. I have a friend who is much older than me and he can't sleep at night because of the bn. He struggles and dozes but never quite gets the full sleep he requires. Most of us are probably in that corner anyway.
If you have found what helps to reduce or camoflage it share it.
If you have any web sights for info share it.
Thanks for input:
Unk-j