Noise induced injury occurs due to:

Noise-induced injury primarily results from one significant exposure or event, typically referred to as an acoustic trauma. This type of injury occurs when an individual is subjected to an extremely loud noise, such as a gunshot or blast, that can cause immediate damage to the hair cells in the inner ear, leading to sudden hearing loss.

While irregular exposure to noise could contribute to hearing issues, it is the acute, high-decibel exposure that is most critical in defining noise-induced injury in a clear and direct manner. Long-term exposure to loud environments can indeed result in hearing loss, but this is usually termed noise-induced hearing loss rather than an acute injury. Emotional stress is not a direct contributor to noise-induced injury, even though stress can exacerbate hearing sensitivity in some individuals.

Therefore, the emphasis on one significant exposure or event highlights how immediate and intense sounds can lead to direct physical damage to auditory structures, classifying it clearly as a noise-induced injury.