What is the purpose of the middle ear?
a. to convert sound waves into mechanical waves.
b. to evaluate the quality of sound
c. to collect and focus sound waves
d. to convert mechanical waves into electrical waves.

the cavity also plays a very important role in a person's ability to hear. inside the middle ear, three small bones (ossicles) form a chain and conduct sound vibrations from the eardrum to the inner ear. once in the fluid-filled inner ear, sounds are converted into nerve impulses and sent to the brain.

digestion

it excretes wastes