I was told albeit after the fact that the ringing is a result of damage that has already occurred so you need to tell them ASAP to prevent further damage. Also this "ringing" as they call it really can manifest itself differently with each of us. I never heard a ringing, I would describe it more like a very faint electrical hum which was not constant. I was never tested pre Tx, only post and they told me that I have permanent loss in my high frequency range in both ears. Not bad enough to wear aids but I have trouble singling out a voice in a group of people; can't hear my cell ring that great; can't ever hear a cell phone ring on a TV show; trouble with female voices (now that can work out to a male's advantage!) and have trouble with emergency vehicles which has led to a few scary intersection moments!