Why does my refrigerator make a high pitched noise?

In treating sensory dysfunctions, a "just right" challenge is used: giving the child just the right amount of challenge to motivate him and stimulate changes in the way the system processes sensory information but not so much as to make him shut down or go into sensory overload. The "just right" challenge is absent if the activity and the child's perception of activity do not match. In addition, deep pressure is often calming for children who have sensory dysfunctions. It is recommended that therapists use a variety of tactile materials, a quiet, subdued voice, and slow, linear movements, tailoring the approach to the child's unique sensory needs.