I agree with the silliness of 192kHz, but not 24-bits. Here is why: In typical PCM recordings, like CDs, mid-range frequencies (e.g. 1kHz to 4kHz) are recorded with lower amplitudes because our ears are more sensitive to them. Sampling theory is correct and 16-bits can reproduce any waveform with ~100dB of range, however, in a complex waveform consisting of low, mid and high frequencies, the mid- and hi-range frequen…
There's also the fact that you can FEEL some sounds that you can't hear. Chris Randall of Sister Machine Gun (at least used to?) use a low-frequency generator at live shows to produce a sound that the audience could feel but not hear in order to make the music more intense. I suspect that you'd gain some of that effect with a larger bit size. ...or I could be completely wrong. Whatever.
What you feel is parts of your body resonating (because the low frequency sound is exciting modes of your body). This is unlikely to happen at high frequencies, partially because it would necessarily be much smaller parts of your body (see [0] for a diagram of typical body resonance frequencies) which we probably don't feel and because attenuation of sound greatly increases at higher frequencies (for example, see [0] for air), making it likely impractical to excite any such modes. My guess is that you might cause some tissue damage if you had significant ultrasonic excitation in your body (see [2] for something that may or may not be true...).
[0] http://physics.stackexchange.com/questions/37543/does-the-hu... [1] http://www.kayelaby.npl.co.uk/general_physics/2_4/2_4_1.html [2] http://www.tovatech.com/blog/4376/ultrasonic-cleaner/ultraso...