Hair Cells Are Fragile
Hair cells are easily damaged, for example, by listening to extremely loud music. As you grow older, hair cells at the high frequency end of the cochlea also tend to wear out.
The pictures below show electron micrographs of healthy hair cells (left) and hair cells after exposure to excessive noise (right).
In mammals, dead hair cells do not grow back. Damage to hair cells is a leading cause of hearing loss. Take care of your hair cells!
Picture credit House Ear Institute