The sound that repels troublemakers

[Rainraven]

Haha I can only hear the 17.7KhZ and well I can almost make out the 18.8kHz but after that it is completely silent.

You must be OLD

[Spaniard_Truth]

I can only hear up to 14.1 khz. I can hear up to 15.8 VERY faintly, but it doesn't annoy me. 14.1 is the highest I can hear properly. This is probably because I've had earphones plugged in since I was about 9.

Edit: Actually, I moved the position of my ear relative to my laptop, and I heard up to 15.8 quite clearly.

[Vargtand]

You must be OLD

Hey I have perfect hearing!

[Tabiti]

I think I can hear between 12 and 14 and 18 and 20 ranges. I listen to music on headphones since I was 14, so I don't think I have the perfect hearing anymore.
Low blood pressure often causes to hear a constant noise as well.

[Bloodeagle]

Please keep in mind while you're playing around with this:

a) digital compression on such sounds often means you're hearing audio artefacting rather than a pure tone, allowing you to "hear" a tone your ears can't perceive, which brings me to

b) it is probable that whatever speakers or headphones you possess are not audiophile grade and as such are likely incapable of reproducing sounds above 20Khz (the ultrasonic range): that is the most common upper frequency humans can hear and as such is the upper end of most reproduction equipment's frequency range.

If, on the other hand, you have some higher grade equipment and a tone generator (or lossless recording) you would be able to test this definitively.

Is it possible that since most people cannot perceive sounds above 20khz, they might actually hear them subconsciously?

[anonymaus]

Is it possible that since most people cannot perceive sounds above 20khz, they might actually hear them subconsciously?

Certainly. This is actually a pretty common principle in testing for these things as people who are told to listen for something do listen for it: the human mind is only too happy to oblige this search and as one's brain will change the focus of hearing around until it catches something. I think in uncontrolled situations this is likely coil whine from nearby electronics, or the wretched sound of an AC adapter which I unfortunately can hear from many rooms away.

The blind tests (obviously with appropriate equipment for the ultrasonic frequencies) solve that problem for the most part.