Hyperesthesia (or Hyperaesthesia) is a condition that involves an abnormal increase in sensitivity to stimuli of the senses. Stimuli of the senses can include sound that one hears, foods that one tastes, textures that one feels, and so forth. Increased touch sensitivity is referred to as "tactile hyperesthesia", and increased sound sensitivity is called "auditory hyperesthesia".
Excessive consumption of caffeine can temporarily induce this condition in humans, due to excessive stimulaton of the spinal cord, as well as the cortex and medulla in the central nervous system. However, this is far from the only cause, and usually wears off after 3-5 hours.