Jem, I think we all worry about this.
I have this problem as well, and I started a post a year ago about
how I attempted a cure for it.
The good news is that if you are able to fully manage the noise exposure, it does indeed get better. And one can aggravate it by playing the system too loud.
Since I put in acoustic treatments this winter, I've noticed less of a problem, partially because I can play the system softer with greater detail, now that the room ringing is gone.
In many ways, the 'ringing' in the ears is exacerbated by room 'ringing' in the mid and high frequencies.
I personally believe that our speakers are actually capable of so much clean high-frequency content, radiated in such large quantities in a dipole fashion, which if not acoustically well managed in the room, can indeed cause resonances and overload at certain frequencies. These higher pressure room resonances can fatigue the ear, and if exposed to it long enough, cause tinnitus.
The cure is to start treating the room correctly as well as ensuring placement is ideal.
Unfortunately, it takes some measuring equipment to really tell what placement and / or treatments are improving things and at what frequencies.