... but I think it's unfair to say that we cannot feel at much higher frequencies. I believe Christian was fair with his tests and that it somehow proves that the frequency range is more complex that what we currently know.
The human animal evolved from others animal that used to live in water. And in water the sound you can "hear" is much higher in the frequency range. The same way as our brain have a reptilian part (this is the technical name), maybe our body have some reminiscents of our origins.