Answers:
loud music, an uncomfortable chair, and a fidgety neighbor.
Step-by-step explanation:
An outer distraction, as common sense would have it, implies that we are referring to a kind of distraction based on external factors that impact on you and prevent you from listening closely and attentively to something or someone.
Certainly loud music would become a nuisance when trying to listen closely to something. Also, an uncomfortable chair can cause you to focus on your sitting position and the bodily discomfort that it causes, making you inattentive. Finally, if you have a fidgety neighbor who is walking around his apartment and moving stuff around, that can make you lose focus, too.