Which of the following is an example of sensory adaptation?

What is the definition of a "just-noticeable difference"?

As a part of a research study, Carlos was presented with a sound. He was instructed to press "S" (for “same”) every time that he heard the same sound, and to press "D" (for “different”) every time he heard a different sound. At the end of the test, Carlos was informed that he correctly pressed "S" for every same sound, but incorrectly identified many of the different sounds as “same sounds.” Carlos' ability to detect signals would be described as which of the following?

Signal detection studies measure an individual’s ability to detect certain stimuli. They involve exposure to stimuli at varying magnitudes and ask subjects to detect any changes in their perceptual experience of the stimuli (i.e. the just-noticeable difference). Perceiving magnitude differences in stimuli depends on the type of sensory experience (e.g. touch or sound) and is based on proportional rather than absolute amounts.

Imagine a hypothetical study that asked participants to perceive changes in amplitude of a sound stimulus. In this experiment, the researchers wanted to know how much the amplitude needed to change in order for an individual to detect a difference. They decided to test the just-noticeable difference at three different amplitudes: low, medium, and high. Participants in each category listened to the initial sound, and then the amplitude was increased or decreased slightly until participants detected a difference.

Imagine that this study used a forced choice design in which participants had to select "the same" or "different" after hearing a pair of sounds at different amplitudes. As the amplitude of the comparison sound increased, which type of signal detection response would be most likely, regardless of the initial sound?