When Ann went to her doctor, he gave her a hearing test. During the test, the doctor presented tones to Ann through earphones. The tones varied in volume (from very loud to very soft). The doctor asked Ann to raise her hand whenever she heard a sound. The doctor was testing Ann's .

Absolute threshold

Explanation: The absolute threshold is the minimum amount of energy, or quantity of a stimulus, required for it to be reliably detected at least 50% of the time it is presented. In this example, thedoctor is trying to find the quietest sound Ann can reliably detect (i.e., the absolute threshold). In contrast, to determine a difference threshold, the doctor would need to ask Ann if she perceived two sounds as being the same or different volumes.