Final answer:
Bobbi's increased awareness of the ticking clock during her exam is an example of habituation, where her response to a repeated stimulus (the ticking sound) changed over time, allowing the once ignored noise to become more noticeable.
Step-by-step explanation:
At the start of the exam, Bobbi became increasingly aware of a ticking clock on the wall, which represents a psychological phenomenon known as habituation.
Habituation is a decrease in response to a stimulus after repeated presentations. Initially, Bobbi was focused on the exam and not distracted by the ticking sound. However, as time passed and she possibly became more accustomed to the exam environment or began to shift her focus, she started noticing the distracting background noise. This change in perception can occur for various reasons, including a decrease of other stimuli competing for attention, a shift in her sensory or cognitive focus, or simply the passage of time making the consistent ticking more salient to her conscious perception.
This experience is an example of how our sensory systems, and ultimately our brain, can filter out distracting sounds to allow for concentrated focus on specific tasks like an exam. Yet, over time, our brain might change this focus, letting previously ignored stimuli become more pronounced in our conscious experience.