What Is NIHL?
When we are exposed to harmful noise — sounds that are too loud or loud sounds that last a long time — sensitive structures in our inner ear can be damaged, causing noise-induced hearing loss (NIHL). These sensitive structures, called hair cells, are small sensory cells in the inner ear that convert sound energy into electrical signals that travel to the brain. Once damaged, our hair cells cannot grow back.
Scientists believe that, depending upon the type of noise, the pure force of vibrations from loud sounds can cause hearing loss. Recent studies also show that exposure to harmful noise levels triggers the formation of molecules inside the ear that contribute to hair cell damage and NIHL.
When a person is exposed to loud noise over a long period of time, symptoms of NIHL will increase gradually. Over time, the sounds a person hears may become distorted or muffled, and it may be difficult for the person to understand speech. Someone with NIHL may not even be aware of the loss, but it can be detected with a hearing test.