In psychology, absolute threshold is the smallest amount of intensity from a stimulus that is detected by a person's senses. These senses include vision, hearing, taste, touch and smell.
An example of absolute threshold for hearing is the quietest tone that is detectable by a human's sense of hearing without any other interruptions or other sounds. The absolute threshold for vision is the smallest amount of light that is seen by the human eye. An example of touch absolute threshold is the point in which a person begins to feel the heat from fire. For smell, it is the slightest hint of a scent a person is able to detect when in a room. In reference to taste, the absolute threshold is the minimum level of flavor a person can detect.
Each sense has its own level of absolute threshold, and for each person it can vary. The term absolute threshold is often used in experimental research and in neuroscience. In addition to absolute threshold is the just-noticeable difference or difference threshold. This is the smallest level of stimulation that required for a person to determine when there is a difference between two stimuli. The main concept of absolute threshold is detectable at least 50 percent of the time.