At Israel21c we read about the Snoezelen method of Controlled Multi-Sensory Intervention (CMSI) therapy:

Snoezelen (from the Dutch ‘to doze’ and ‘to sniff’) is the original and most commonly used tool for the application of CMSI.
The concept of Snoezelen was defined in the late 1970’s by two Dutch therapists, Jan Hulsegge and Ad Verheul. While working at the De Hartenberg Institute in Holland, a center for people with cognitive disabilities, the two therapists learned of the positive responses a colleague was able to elicit from his severely challenged clients when they were exposed to a sensory environment he had assembled. The environment stimulates the primary senses of sight, hearing, touch, taste and smell, through the use of lighting effects, tactile surfaces, meditative music and the odor of relaxing essential oils.

The Snoezelen provides a bland, soothing environment onto which various types of stimuli can be imposed. When the client – whether a child with special needs or an adult who is suffering from brain injury, stroke, or dementia – enters the Snoezelen he finds himself in a space whose floor is covered with large off-white mattresses, and whose walls and ceiling are upholstered with soft off-white padding. He makes himself comfortable and, together with the accompanying therapist, relaxes in the low lighting and the soft regular music.

After a time, the therapist sets a nearby object rotating or vibrating, releases an aroma, or lights up one of the many optical displays in the room; there are illuminated columns of liquid through which bubbles of various sizes rise; a Catherine wheel-like display of lights; skeins of multi-colored optical fibers; and reflecting mirror balls.

A CMSI room can be used in two ways. The first gives clients temporary relief from their disabilities: the hyperactive are calmed by elimination of stimuli to which they are hypersensitive, the passive and non-communicative find a channel though the wall that separates them from the rest of the world. The second uses the room as a diagnostic and therapeutic tool. The enabling approach to therapy mirrors the calming effect of the Snoezelen. Instead of applying a pre-planned program, which the client might find stressful, the therapist responds to the client’s lead and preferences.