Just as the anticipation heightens the intensity of play, sensory deprivation heightens anticipation.  Being blindfolded, ear plugs, loss of one sense makes the others more acute.  When you cannot see, every click of a heel or boot on the floor boards draws a shiver down your spine – if you cannot see or hear, every touch on the skin, a breath on the neck is amplified.  Sensory deprivation can increase the intensity of a session greatly without having to increase the levels of pain or sensation – the lack of sensation itself followed by heightened anticipation and resolution of that expectation can reap rewards and leave you a quivering mess (in the best possible way).