Sound detection, hearing allowance, and balance maintenance are the main functions of the ear.
Hearing
The most basic function of the ear is hearing. The following is the short description of the hearing process :
The first step is when the pinna collects external sounds that enter through the meatus or ear canal as sound waves. The ear drum begins to vibrate as these sound waves strikes. These vibrations pass through to the three ossicles of the middle ear (hammer, anvil and stapes) where they are amplified. As the transmission proceeds, the vibrations first hit the hammer, then the hammer pushes the anvil, and the anvil hits the stapes.
The vibrations are finally interpreted as sound in the brain after being transmitted and transformed into nerve signals by the cochlea (snail shaped component of the inner ear). This is due to the connectivity of the oval window of the inner ear to the edge of the stapes. When the stapes vibrates, they always transmit the sound vibrations to the inner ear.
Balance
The other important function of the ear is to help maintain balance. Oriented at the right angles to each other are three semicircular canals of the inner ear. Whenever the head is turned or change position, the resulting movement of fluids within these canals help the brain to identify or detect the extent of movement and positioning of the head.
In response to gravity, another part of the inner ear sends information to the brain when the head is held still in a stagnant position.
The above information thankfully comes from the entmags.org.com at the following link.