"96Khz or 192khz? - 44.1 Khz is a higher 'resolution' already than my (and your) ears can hear. At 96khz and with the right equipment you are either tormening your dog or delighting him with bits of your music that you will never hear."
Higher sample rates improve the phase accuracy of high frequencies, not an issue for mono but in stereo it helps you pick up the direction a sound is coming from.
Higher sample rates also make the anti-aliasing filters much easier to design, and reduces their effects on the audio you can hear.