Refer to figure. 
The human ear is responsible for two functions, sound reception (senses air vibrations) and balance-acceleration detection (senses accelerations of our body). To achieve these functions the human ear consists of three parts, outer, middle and inner ear.

OUTER EAR 
The sound vibrations are entering the ear by the pinna, and then they travel through the auditory canal (Meatus) and finally reach the ear drum (Tympanium), which in turn vibrates.

MIDDLE EAR 
Attached to the ear drum there are three tiny bones called ossicles (the malleus, incus and stapes or hammer, anvil and stirrup). Their purpose is to act as a bridge and transfer the sound vibrations from the outer to the inner ear. Part of the middle ear is the Eustachian tube which is connected to the back of the throat and equalizes the pressure between the middle ear and the environment.

INNER EAR 
The inner ear is divided into two parts:

1. Cochlea: The cochlea has a sensitive membrane that senses sound vibrations and produces the nerve impulses that the brain then interprets as sounds. This part of the inner ear is responsible for sound reception.
2. Vestibular Apparatus: The vestibular apparatus is the part of the inner ear responsible for balance-acceleration detection with a purose to provide to the brain a model of spatial orientation and help it control other systems of the body. The vestibular apparatus consists of the otoliths that sense linear acceleration and gravity, and the semi-circular canals that sense angular acceleration.

Ossicles → They transfer the sound vibrations from the outer to the inner ear. They do NOT produce nerve impulses. 
Cochlea → It senses sound vibrations and produces the nerve impulses that are transfered to the brain. 
Semicircular canals → They sense angular accelerations 
Tympanic membrane → It vibrates with sounds. It does NOT produce nerve impulses.