Solution:

Eustachian tube connects the middle ear cavity with the pharynx. This helps in equalising the pressures on either sides of the ear drum.

Ear ossicles(Consiste of malleus,incus,stapes)
Amplify and transmit
the vibrations of the
tympanum to the
internal ear.

Movements of the head bring
about the movement of the endolymph present
inside the vestibule and the semicircular canals. This
causes movement of the sensory hair cells and
generates impulses. These impulses are transmitted
by the vestibular nerves to the cerebellum, and the
equilibrium of the body is maintained.