Do you know what causes listener fatigue and how it can be measured? I'm reasonably confident that I don't know what causes it, nor what the units of measurement are.
I've been in studios when musicians are being recorded. After a very short while I found trombones close to me made me want to move away. Live instruments (drumkits, some brass etc.) are very loud and are hard to listen comfortably.
It might be that listening to highly accurate reproduction at accurate sound levels is naturally fatiguing and systems that don't induce "listener fatigue" are not accurate.
An accurate system can sound fatiguing as well - if what's coming out is too bright, too loud, or too distorted (for whatever reason). The fatigue from clipping I reckon is from a combination of (usually) loud HF (from the waveform hitting supply like a sprinter into a wall of bricks!), and unpleasant sounding distortion. Mostly the former.
About live brass instruments, it's likely down to amplitude. There's a muscle that tightens your eardrum when constant loud sound is present. It's a natural defense mechanism for hearing protection. The brass, being loud and sporadic, bypasses this protection for the 1/4 - 1/2 second at the beginning of its parts. If it's in and out dozens of times in a few minutes, it adds up.
When loud signal goes down the nerve from your ear to your brain, electrolytes (for transmission) are depleted. If you keep successively stimulating the nerve in its depleted state, that is when damage occurs, and quick (the kind where you can still hear quiet and high (because the cilia in your inner ear are fine), but you have trouble separating voices from background music/noise. Before this serious level of depletion you'd have to be at a loud multi-day concert.
Conversely, if you're drinking a lot, 4-6 hours in a single day might be enough (for someone in average health)
You can train yourself to have conscious control over the tightening of your eardrum, so that when you're in the presence of live brass, you can tighten it up!
Problem is, once you're adept at control, it'll take seriously loud music for autopilot to kick in (I mean pain levels, and you're reminded to tighten yourself from the pain more than it happens automatically).
Like anything automatic, it becomes a background task, but you still have to initialize.
If you get drunk at a concert to the point you're not really aware of your surroundings or the difference between pain level 2 and 8, it's possible you'll just let everything in.
Tip: when tightened, everything but treble is attenuated. Kind of like "Loudness" tone control without the bass. After a couple minutes, bass comes up a bit (not from any slackening, because sensitivity is restored, like any other amplitude adjustment situation unrelated to anatomy). Attenuation depends on taughtness, and there's only really taught or slack. Sure, you can hold half way, but it'll take immense concentration, and your brain won't be able to adjust so that what you're listening to sounds like you've got Bass at +1, Treble +4 (like now when you work your 100W RMS amp and 91dB/w speakers hard with Smashing Pumpkins in the sweet spot of your 9x13x8 foot listening room [if you can imagine])
Comprehensive, and the answer you were looking for, I hope.
Any questions?
