Hi-res includes greater resolution (more bits) so should have correspondingly lower noise and distortion. I suspect that has more impact (i.e. is more audible) than the higher sampling rate.
As to ultrasonic content, the usual argument I have heard is that suprasonic tones can mix and generate lower-frequency beat tones that are able to be heard since they fall within the audible frequency range. Note some nonlinearity must be involved for that mixing to occur (and of course sampling is a nonlinear process itself).
No idea if either of those half-brained ideas will correspond to anything j_j or anyone else might say.
IME/IMO - Don
As to ultrasonic content, the usual argument I have heard is that suprasonic tones can mix and generate lower-frequency beat tones that are able to be heard since they fall within the audible frequency range. Note some nonlinearity must be involved for that mixing to occur (and of course sampling is a nonlinear process itself).
No idea if either of those half-brained ideas will correspond to anything j_j or anyone else might say.
IME/IMO - Don