Sound ^
In this example, the slave is secured in a leather sleep sack, and has been for several hours. He has a thick padded 'head trip' hood on (Fetters/MrS HT9) along with some sound defenders (with ear plugs inside). This means that the padding limits any external sound, the yellow 'head phones' cut down external sound but introduce your own - white noise, Theata or hypnotic programming.
You can also explore brainwashing, with sleep deprivation,
This technique allows him to focus in on what you want and to cut away every distraction.

 

Cautions:

Overheating, cramps and panic.
With any advanced SM play you do it with someone you trust, the top has to behave responsibly. You don't leave the house.