I had a magic skill when I was in high school: I could walk into any computer lab and tell you exactly which monitors were on (when the computer was off). I believe this is around 15K.
it looks my hearing drops off between 13k (noticeably quiet compared to 12k) to 14k (can't hear it at all).
Hah reminded me of when I was a kid walking into the living room with a few people around many times and turning off the TV (crt of course) that was just showing a black screen. It was so loud and obvious to me. Now all the TVs seem to have bizarre screensavers
it looks my hearing drops off between 13k (noticeably quiet compared to 12k) to 14k (can't hear it at all).