My hearing’s crap, on that audio test I can hear the tone at 9kHz, I’m 59.

Your audio equipment needs to be physically capable of generating that frequency though, and that’s assuming the source is also physically capable too.

Someone near us has some sort of deterrent thing in their garden, I certainly hear/feel a clicking in the back of my skull when I go by. Bats too, often feel like I am hearing their squeaks, only when out side.

Yes. I’m in my early 30s and can hear those Mosquito things that shop owners put up to stop customers going in their shops.

@Mattyfez – tried a few sources and devices: 9kHz is audible; 9.5kHz is audible but noticeably quieter; 9.6kHz is inaudible.

I can hear something ultrasonic anyway, most likely the aliens, but listening to tht audio link,that stops, and it comes in at 11k for me. I’m 59 last year

Every few years I go for a medical which includes hearing test. Every time I am complimented on my hearing ability and the doctor doing the test gets all excited about it, as if it is something I have somehow managed to achieve off my own back. I can apparently pick up things at the extremes of human ability. I can hear all sorts of buzzing and high pitched things day to day that no one else seems to be able to. I didn’t find out about this until well into adulthood, perhaps if I had known about it when in my youth, when your hearing is better, I could have done something useful with it.