Answer:
Amber's detection of the increase and decrease of volume is an example of difference threshold.
Step-by-step explanation:
The difference threshold is the minimum amount of change needed in a stimulus in order to be perceived as a change. It is a small amount but enough to be a noticeable difference.
This is an example of a difference threshold since it is barely any amount but it was enough for Amber to notice the difference in her roommate's music volume.