Sensory adaptation is the process by which our sensory receptors become less responsive to constant stimuli over time.
This is the minimum level of stimulus intensity needed for a stimulus to be detected half of the time.
This law states that the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus.
A theory predicting how and when we detect the presence or absence of a faint stimulus (signal) amid background stimulation (noise).