Any sampler built after about 1988 can do 44.1KHz @ 16bit, the exact same as audio CD (and veru often MUCH higher qualities are available....96Khz @24 bit is common), the 44.1Khz, by way of Nyquist theory, gives a theoretical highest recordable pitch of 22.05Khz, which is as high, or higher than medically perfect human hearing can detect (the vague whine, the sort of "aura more than sound" that a CRT television makes....you know the one that lets you tell it's switched on even with a black screen and the sound down, is 16Khz (erm on a PAL TV in the UK anyway), to give you some idea of how high that is). And 16bit gives you 65536 graduations in volume from silence to loudest, and provides a signal to noise ratio of 96dB (which is LOADS)
The best way to get it to sound "live-ish" is to bring the vocal output of the sampler in to the mixer on it's own, and treat it with the same effects being used on the "real" vocals.
I am undecided as to where the various "multi-barney" noises come from, it COULD be ADT ( automatic double tracking, using tiny delays to make it appear there are multiple tracks of vocals playing) however, this tends to sound chorussy and can be a real kamikaze move to use live.
Don;t get me wrong, on some tracks, where other "tape" parts are needed, I have no ddoubt the backing vox live on the tape, but when it's live band and sequencers ( not so much if at all nowdays), the sampler is defo the way to go. Any time the SNSS have done vocals live, that's how we have done it too...tho maily so we could goon around with the sampled vocals in the improv bits ;)