Do you have tinnitus or any hearing impairment? This is an interesting discussion on hearing aids and HA-related issues that you must read.
[1] http://wattsupwiththat.com/2011/09/10/a-note-about-hearing-technology/

About tinnitus (ringing in the ear), with which I am afflicted, in a reply to one of the comments that mentioned tinnitus, Anthony Watts points to a remedy that may help. I have not tried it yet, but I will, because my problem with tinnitus is gradually becoming worse. It has begun to impair my ability to hear well.

You may wish to check out the link identified by Anthony Watts, if for no other reason than to find out what tinnitus is, what causes it and to listen to what it sounds like. The “High Frequency Buzzing” sound track at that web page sounds exactly like the tinnitus that bothers me. Take a look at this: [2] http://www.quietrelief.com/

“Tinnitus is common; about one in five people between 55 and 65 years old report symptoms on a general health questionnaire, and 11.8% on more detailed tinnitus-specific questionnaires.” [3] http://en.wikipedia.org/wiki/Tinnitus