perception

a point above which a stimulus is perceived and below which it isnt

when we first become aware of a stimulus

defines the absolute threshold as the smallest amount of stimulus (sound or light....) that can be observed or experienced

the intensity leve of a stimulus such that a person will have a 50% chance of detecting it

intensity that gives a person less than 50% chance of detecting the stimulus

worked on the problem of how we judge whether a atimulus,(ex:loud music) has an increase or decrease in intensity