To get back to the topic of this thread. RWBadley, as Psacanli has suggested, isolation and conditioning of the entire system will help. However, I believe the room is actually the biggest factor in reducing the effects of ringing in your ear apart from avoiding listening at high volumes. Apart from standing waves and modal ringing in the room, midrange and high frequency reflections can actually cause a lot of displeasure to the ear especially if the acoustics of the room is a bad one. Previously I have only diffusors at the rear wall. Just when I felt the reflections might be too much, I placed some of my left-over absorption panels at the rear, in other words a mix of absorption and diffusion, and the net effect is pleasingly advantageous not only in improving the room acoustics but in reducing the intensity of ringing in my ear as well.
If room acoustics have not been addressed, I would think it is worthwhile to look into it. You have to realize that loud noise exposure which includes high intensity music is a very common cause of tinnitus. Apart from listening at low to moderate volumes, a good room will definitely help alleviate the problem to a lower level. The effects of the room will be 10X greater in comparison to the CD player IMO.
Just food for thought.