An isolation hood is a more extreme version of a bondage hood. It is designed to disorientate the wearer by keeping them in total darkness and making it very difficult to hear anything. The heavy leather used in the construction of these hoods is usually enough to block out most noise. However, ear plugs can be used to block out any residual sounds that penetrate the hood. A few designs incorporate pockets to fit headphones in. This allows the dominant partner to play white noise, music, or spoken words to the the sub, for example to shut out any sounds that might otherwise be audible, to cause sleep deprivation or to reinforce a sense of humiliation verbally.
Most isolation hoods also incorporate gags to enhance the sensation of loss of control and helplessness felt by the victim. This is potentially extremely dangerous, as blocking all access to air will result in rapid asphyxiation. The safety warnings regarding gags also apply.
Part of the thrill of wearing an isolation hood is the sense of being cocooned in a dark space. For this to be effective, the hood needs to fit tightly to the head. The most common technique manufactures use is to provide a set of laces at the back of hood which can be adjusted to pull the hood tight around the victim's head. A variation is to have two sets of laces on either site of the hood. This has the advantage that the hood will have a much greater range of adjustment (the same hood could fit both a man and a woman's head) but will need to be made from a softer and more flexible leather. A less common technique is to have an inflatable bladder at the back of the hood. The hood is first zipped on to the victim; once this is done, the bladder is inflated pulling the hood tight.
Most isolation hoods focus on how they control the victim's sight or lack of. The simplest simply dispense with eye holes alltogther. Many people, for whom powerplay is important, like to control when and if their sub can see. The most common technique is to provide removable blindfolds which can be attached to the hood by velcro, press studs, or straps. An alternative design uses an outer hood which can be zipped over the inner (containing the mouth and eye holes) to prevent the sub from seeing.