Sensory deprivation is the practice of temporarily 'removing from' or depriving someone from making uses of one or more of the senses.
For total sensory deprivation, one must be deprived of all five senses:
Normally, it is desirable for a bottom to be left with at least one sense, typically touch. With only physical feeling left to experience his/her surroundings, the sense of touch - and its anticipation - is greatly heightened.
It can be hard to make sure that someone can hear nothing at all, however well their ears are insulated. Ear plugs and isolation hoods are useful, but rarely 100% effective. A common ploy to get around this is to do what is practicable to block out sound and also make them hear a noise that will overshadow anything else and that their mind will largely ignore after a time. This is most easily done with a pair of headphones connected to a sound source.
The sound source is most effective if using a bland sound, which need not be played loudly. Various sounds can be played from a recording or created from equipment, some of which may be around the home already. The Wikipedia has an article on Colours of noise (technical).
- White Noise
- This is like a very uniform hissing sound. White noise is a random signal with a flat power spectral density. In other words, the signal's power spectral density has equal power in any band, at any centre frequency, having a given bandwidth. Turn on an amplifier without any input from radio, CD, etc. and crank the volume way up - chances are that you'll hear something close to white noise.
- Pink Noise
- Pink noise is a variant of white noise. A fairly close approximation is the sound of continuously falling rain onto various hard surfaces. Pink noise is white noise that has been filtered to reduce the volume at each octave. This is done to compensate for the increase in the number of frequencies per octave. Each octave is reduced by 6 decibels, resulting in a noise sound wave that has equal energy at every octave. Some hi-fi graphic equalisers will generate pink noise in a test mode. Also, some 5:1 or 7:1 sound systems will do so as an aid to adjusting the sound levels across the various speakers.
- Brown Noise
- So called because it is supposedly the equivalent of listening to Brownian motion. Brown noise is similar to pink noise, but with a power density decrease of 6 dB per octave with increasing frequency (density proportional to 1/f2) over a frequency range which does not include DC. Also known as "random walk" or "drunkard's walk" noise. An approximation of brown noise can come from a radio or television receiver that is off-station. Brown noise is not to be confused with the brown note.
- Mains hum
- Most people have heard mains hum - it is a noise often associated with faulty electrical equipment. It has a frequency of 50 Hz in most of Europe and 60 Hz in North America. Using mains hum for sensory deprivation will sometimes induce a feeling of mild panic — not always beneficial.
As with sound, it can be hard to prevent people from smelling things, although a gas mask fitted with a good filter will do the job. Otherwise, a continual and overpowering smell that hides anything else will have similar effect. Care must be taken with the choice of aroma as many of the more powerful and obvious ones, such as menthol, can be unpleasantly irritating in large or continual amounts.
This is quite straightforwardly achieved by sealing the mouth shut, as people can only taste things in their mouth.
Aftercare and safety
Someone in sensory deprivation, especially if it is total or nearly so, will experience time distortion. Most likely, this distortion will mean that a few minutes of real time can seem like as much as an hour to them; their tolerance should be measured in their perceived time, not real time. Under some circumstances, such as during extended orgasm or sensory pain, the opposite can occur and what may be two hours or more could seem like just a few minutes; this can affect their dehydration and also leave them with an unhappy feeling of having lost a part of their life, despite having just enjoyed themselves.
Though sensory deprivation has been shown to have some therapeutic benefit if applied over a short time, long-term sensory deprivation is very dangerous and is considered to be torture by most human rights groups. Therefore, it is strongly advised that any session involving a high level of sensory deprivation be limited to no more than one hour. Also, it is doubly important that the dom/domme be conscious of the mental state of their sub.
One way to offset the danger is to practise partial rather than total sensory deprivation. For example, the use of a blindfold alone, even over long periods of time, will not usually cause mental distress. However, care must still be taken as, left to their own devices, a blindfolded sub can easily become disoriented and injure him or herself.
- www.bondage-guide.net: Short article on sensory deprivation.