Which occupational sources are commonly associated with the military?

The correct choice highlights that weapons, machinery, and vehicles are common occupational sources associated with the military. These items are integral to military operations and training, exposing personnel to various levels of noise and vibration. The use of weapons, from firearms to heavy artillery, generates significant sound levels which can contribute to hearing loss over time. Similarly, machinery such as tanks, aircraft, and other vehicles operate at loud volumes and involve vibrations that may also pose risks to hearing.

In contrast, while sewing machines, computer keyboards, and office printers are commonplace in many civilian work environments, they do not represent the primary sources of occupational exposure in a military context. These items are not typically associated with the distinctive noise hazards that military personnel usually encounter. Thus, the focus on weapons, machinery, and vehicles as occupational sources aligns with the unique nature of military environments and the associated risks to auditory health.