S0me1X - I don't know what planet you're from, but here on earth, our hearing range is only from about 20hz - 20,480hz
Anything lower than 20hz is sub-bass and not really translatable into anything but vibration (as far as our ears go)
High-end subwoofers (i.e. Velodyne) go down to 12hz at the bottom.
Anything higher than 20khz is beyond human hearing unless you're a child (children can hear up to 24khz sometimes), a dog, or a dolphin.
*edit*
Just read that if you're an avid music listener (rock, etc) then your hearing is likely limited to 15-16khz on the high end. So even 20,000 is overkill for many people.
And the bats!! The bats! They can hear high pitches too. Find some "quality" headphones that can produce higher than 20khz, crank 'em up and aim them at the sky.. watch those suckers hit walls!