Got a similar one! Was playing my normal summer job outside, just off the terrace at the Merrick Inn in Lexington. A long-time friend and his wife had brought his parents to dinner.They were sitting on the terrace, about 30 feet from me. I kept hearing a high pitched squeal, and it was driving me nuts. I kept fooling with the eq during tunes, turning down the mains, fooling with internal keyboards settings...anything and everything I could think of. This went on for almost a full set. Finally, in frustration, I took a break and turned off everything. the squeal was STILL there!

Turned out it was the old gentlemans hearing aid. It was almost as loud as me. He couldn't hear it, and his family was used to the noise.

Obviously, I didn't put much stock in the compliments the old man gave me on the music.

Sadly, he died last year...glad I got to meet him.

russ