Measuring Sensory Adaptation

In the context of sensory processes, consider the phenomenon of sensory adaptation, which refers to the decrease in sensitivity to a constant stimulus over time. An experiment is designed to measure how participants respond to a continuous auditory stimulus. Researchers play a sound at a constant volume for an extended period while monitoring participants' ability to detect brief interruptions in the sound. Given this experimental setup, which of the following concepts is most directly related to the decline in participants' ability to notice interruptions as the sound persists?