In reply to:

Assuming a person gets listening fatigue, would the affected ear still be bothered 12 hours later?

Not a doctor, but have had a LOT of experience with listening fatigue (was a soundman for a LOUD country rock band). If you're still having trouble 12 hours after the fact, I seriously doubt it is caused by listening fatigue.

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton