Is it possible to get a hearing aid that helps block out tinnitus? My father in law says that he won't wear his as it amplifies the tinnitus. Ive suggested he goes back to see someone about it though been 3 times.
There is certainly a device of which you mention, but not all tinnitus sufferers will benefit. I have given you a web site which explains in simple terms how this might help.
The only way is for your FIL to his Audiology Dept which is a part of the local hospital and ask if he could try a "Tinnitus Masker.Not all people will benefit.
http://www.hear-it.org/A-masker