Noise-induced hearing loss

Noise-induced hearing loss (NIHL) is hearing impairment resulting from exposure to high decibel (loud) sound that may exhibit as loss of a narrow range of frequencies, impaired cognitive perception of sound or other impairment, including hyperacusis or tinnitus. Hearing may deteriorate gradually from chronic and repeated noise exposure, such as loud music or background noise, or suddenly, from an acute, high intensity noise incident including gunshots and airhorns. In both types, loud sound overstimulates delicate hearing cells, leading to the permanent injury or death of the cells. Once lost, hearing cannot be restored in humans.