Habituation is a form of learning in which an organism decreases or ceases to respond to a stimulus after repeated presentations. Essentially, the organism learns to stop responding to a stimulus which is no longer biologically relevant. For example, organisms may habituate to repeated sudden loud noises when they learn these have no consequences. Habituation usually refers to a reduction in innate behaviours, rather than behaviours developed during conditioning in which the process is termed "extinction".
According to the American Psychological Association, sensory adaptation is a phenomenon that occurs when the sensory receptors become exposed to stimuli for a prolonged period. The receptors lose their ability to respond and develop a diminished sensitivity to the stimulus. Specifically, continued exposure causes the brain cells to pay less attention to the stimulus and decreases the reaction to the particular sensation. This can occur with all of our senses: sight, hearing, smell, touch and taste.