Does the ear heal itself?

Damage to the eardrum is permanent.

Answer Extra: 

Noise-induced hearing loss primarily damages the outer hair cells in the cochlea or inner ear.  Damage can be temporary or over time, damage is cumulative and permanent.(1) A ruptured eardrum usually heals within a few weeks without treatment. Sometimes, you may need a procedure to promote healing of a ruptured eardrum, or need surgical repair for a ruptured eardrum. (2)

sources: (1) (2)