There are three parts of an ear that can hear sound:
a) outer ear b) Middle ear c) Inner ear
1. Outer Ear[]
This is the external part of the ear. This part of ear can be seen from outside.It collects the sound and focuses it to the eardrum. The sound then vibrates.
The part of outerear that can be seen is called pinna.
2. Midle ear[]
This portion of ear is inside the eardrum and outside the oval window. This part of ear is very small. The main function of the middle ear is to transfer the sound energy from compression waves to fluid membrane waves.
3. Innner Ear[]
This is the inner part of the ear. It is only presen in vertebrates. Its most important part is cochlea. Its is filled with a jelly-like fluid. The functions of inner ear are very complicated. There are some hair like parts in the cochlea.