What does absolute threshold refer to in sensory perception?

Absolute threshold refers to the minimum stimulus energy needed to activate the sensory system and enable a person to detect a particular stimulus. It represents the point at which a stimulus becomes strong enough for an individual to notice it, thus marking the boundary between perception and non-perception. For instance, in auditory perception, the absolute threshold is the faintest sound that a person can hear.

This threshold is critical in understanding how we perceive various stimuli in our environment since various factors such as sensory adaptation can affect it. It is key to differentiating between perception and non-perception, as a stimulus must reach this threshold before it can be registered by an individual's sensory processing.