How does noise affect hearing?
Sounds entering your ear pass through your eardrum and into the inner ear. Tiny hairs in the inner ear change the sound waves into nerve impulses. Hearing nerves carry these impulses to the brain, where they are interpreted as sound. Different sounds affect different parts of the ear. This allows the brain to distinguish one sound from another, such as vowels from consonants. You are born with about 30,000 hair cells in the inner ear and that’s all you get. If some of these cells are destroyed, the cells are not replaced. The hairs in the inner ear are very sensitive and fragile. They can be destroyed by noise in 2 ways. A very loud and sudden noise can immediately destroy the hairs in much the same way a hurricane knocks down trees. More often, the hairs are hurt by stress from chronic noise. Overstimulation by ongoing noise creates chemicals that damage the hairs.
