Diki,
This is the situation that I posted about a month ago and that a few of you helped me with. I've been having this problem since.
It IS an unamplified acoustic piano, but it's "bottom heavy" to begin with...strong bass notes...and very much out of tune. I think this is what's causing the irritation. I call them "dirty sound waves!"
I took a reading from where my physical ear sits and measured the sound at mid-70 db. If I'm correct, that's the level where prolonged exposure at that volume causes damage.
So it's either that or the "dirty sound waves." I'm thinking it's probably BOTH.
MC