HEARING CONSERVATION

1. How hearing occurs

• Sound waves cause ear drum (timpanic membrane) to vibrate
• Vibrations are transmitted through the middle ear bones (malleus, incus) to the fluid in the inner ear (chochlea)
• Hair cells located in the inner ear change movement into nerve signals that are passed to the brain by the chochlear nerve

2. How hearing loss occurs

• Exposure to high levels of sound cause damage to the hair cells in the inner ear
• Damaged hair cells cannot be replaced or restored
• Damage to hearing is permanent