Do supertweeters matter when we cant hear past 15,000 hz?


So I have read that studies of the brain have shown that frequencies above audible are still somehow processed and generate a sense of ease, well being when associated with musical playback. As in somehow the range far above hearing is stimulating a  part of our brain, (or god knows what nuerons) that associates with a natural pleasing sound. Anybody read of this phenomenom? I see some of these supertweters extending to ridiculous highs and wonder if they do this just becauser the design allows for it or are they trying to market this broad range as somehow better. I know I cant hear above 15khz and i doubt most men here above 40 can either. I know a supertweeter helps with the audible high end but what gives with promoting a range to 65kz?
128x128veroman
I remember reading about tests where people could distinguish music with bandwidth opened to 50kHz vs 20kHz.  It is because our hearing operates in time domain more then frequency domain.  Music is processed as wave and not as bunch of frequencies.   Also, higher frequency limit ensures lower phase shift in audible band improving harmonics summing.  My amplifier has -3dB @ 70kHz and it is causing -22 degree phase shift at 20kHz.  Limiting amplifier to 20kHz would cause the same phase shift at about 6kHz affecting the sound, even if your hearing only goes to 15kHz.

I like the extension of a Tannoy ST-100 super-tweeter on top of an Esotar 330D tweeter that has good HF extension of itself. (In the Merlin application the Esotar is down several db at 20khz.) But while the ST is set high at a nominal 18khz, in actuality its third-order crossover rolls down into the more audible mid-treble range. It’s conceivable that a ST is a glorified hearing aid for aging audiophiles with attenuation in their own HF response.

The ST does open up perceived treble extension and air. But put your ear close to it and all you’ll hear is faint chirping.

^^ Its not the ability to hear to 20KHz or beyond that is why you can hear differences in bandwidth outside of the 'audio region'. Please read Kijanki's post above.

When you have a rolloff at or near the audio passband, its audible as phase shift down to 1/3rd to 1/10th the cutoff frequency, depending to a certain extent to the steepness of the rolloff. Phase shift is converted by the ear/brain system (just as distortion is also) to tonality. The result is a tonal coloration. This is why bandwidth is so important.
great response(s). I have ordered an entry level pair of fostex supers to add to my full range unit which drops off at 15khz. i wont know what i am missing until i hear what is not there i figure. thanks for the knowledge