Audio at 54 Khz by Tannoy

I was arguing with one of my friend today about the Tannoy super Tweeter witch can go up to 100Khz of frequency at -18 dB. But my friend was saying that this tweeter is for dumb people because the humain ear cannot go over the 20Khz frequency. I didnt agree with him but he really took out a good question. Any opinion?
Few people can hear beyond 20kHz. Most adults can't even get that far.
There is interesting if rather controversial research which showed that even though humans can't usually hear over 20K there were signs of activity being generated in their brains when they were exposed to frequencies over 20K. A number of people were bringing this up to support SACD and DVD Audio. I have seen measurements and a number of common instruments can produce overtones well up into the 40K range.

I never got to read the scientist's results and testing methodology directly though, only second hand reports, some of which claimed the research was fundamentally flawed.
Ya, as Gpalmer was saying its not completely ludicrous-there may be something there (something above 20khz that actually lends itself to the musical experience). I gather there's not enough evidence yet to confirm it, again I've never searched out any original material on it (which may be interesting.) The only problem then is whether or not the rest of the audio chain, pre, pwr, dac, etc. is up to the job (not to mention a microphone capable of recording up there). I wouldn't say the tweeter is for "dumb" people, I'm not sure what your friend means or knows by it. I believe something like 1% of the population can hear up to 25,000hz. I wouldn't expect any massive changes soon though in speaker design, most of the designers are still working on how to get up to 20khz perfect. At best though I would imagine its level of significance being something debatable like stereo bass being audible (the latter depends alot on the room).
It is true that most of us can hear 15kHz top, but there are harmonic freequencies present in music or any audiable freequencies that will go bellow 40Hz and above 20kHz. Ability to reproduce with presicion these harmonic freequencies will better define a natural sound.
I remember reading a french article claiming proof that we *perceive* sounds beyond our aural limits (through the bones, I believe). If this is the case, wide-bandwidth reproduction is useful: many instruments' harmonics go well beyond the standard 20kHz -- one example being sax (60-70kHz?) -- so why not have them? Likewise, BTW, many instruments' harmonics fall well below their fundamental -- as anyone who has played around listening to the sub alone would know!

Now as to whether such multi-kHz info exists on the s/ware, in the first place, is another matter!
I've read the original articles (I am a neurobiologist) and they are intriguing but not convincing. There are many technical issues which make it difficult to accept that the experimental findings are behaviorally significant. The neurophysiological localizations were particularly strange.