Final answer:
The subject of this question is Physics, specifically the study of noise and its effects on different exposure durations. Very short duration noise, like gunfire and explosions, can have damaging effects on the ear, such as reaching the threshold of pain. Planning noise surveys is important to protect individuals from these noise sources.
Step-by-step explanation:
The subject of this question is Physics. Specifically, it relates to the study of noise and its effects on different exposure durations. In physics, sound is a form of energy that travels in waves and can cause damage to the ears depending on its intensity and duration.
Sources of very short duration noise, such as gunfire, explosions, and cartridge operated tools, can have different effects on the human ear. For example, a loud rock concert with a pneumatic chipper at a close distance can reach the threshold of pain, which indicates a damaging level of sound. On the other hand, a noise exposure as short as 30 minutes per day may also result in damage.
Understanding and planning noise surveys for very short duration noise is important to ensure the safety and protection of individuals exposed to such noise sources.