Apart from hearing, ears also help in maintaining
Weight
Balance
Muscles
Eyesight
The inner ear consists of the semicircular canals and vestibule which is responsible for maintaining balance.
In the ear, cochlea help in balancing the body whereas semicircular canals help in hearing.
We have two ears because: i) It helps our brain to sense that from which direction sounds are coming. ii) In the case of hearing loss in one ear one can still hear from another.