This would be amazing for me. I have had unilateral hearing loss due to mumps since childhood.
One weird instance happened about 25 years ago. I suffered a severe blow to the back of my head. My hearing in my bad ear actually came back for a while but it was like listening to a poorly tuned radio. Proper volume but full of static. After a week or so, my hearing returned back to its normal deficient state. No idea what exactly happened or why.