Which of the following is NOT classified under the functions of cover?

The function of cover in a military context is essential for providing soldiers with safety from enemy fire and environmental elements. The correct choice is related to distinguishing the attributes of cover from other tactics.

Physical obstruction refers to objects that can serve as barriers against enemy fire, helping protect individuals or units. Visual concealment involves hiding objectives or personnel from enemy observation, making it harder for opponents to target them. Protection from elements speaks to cover providing safety from environmental factors like rain, wind, or extreme temperatures.

Noise distraction, while it might be a tactic employed in battlefield scenarios, does not fall under the traditional military classification of "cover." Instead, it relates more to misdirection or diversion strategies. Thus, it highlights different operational techniques rather than the protective qualities of cover, which makes this option stand out as not belonging to the functions of cover.