The parts which function together to bring about hearing are labelled

Explanation

The parts of the ear that enable hearing are the outer ear, middle ear, and inner ear, and the auditory nerve:  

• Outer ear: Sound waves enter the ear through the ear canal and hit the eardrum.  
• Middle ear: The eardrum vibrates and sends vibrations to the malleus, incus, and stapes, three tiny bones that amplify the sound vibrations.  
• Inner ear: The vibrations are sent to the cochlea, a snail-shaped organ that contains fluid and hair cells. The vibrations cause the fluid to ripple, which moves the hair cells. The hair cells bend, which opens pore-like channels that send an electrical signal to the brain via the auditory nerve. The brain interprets the electrical signal as sound.  
• Auditory nerve: Carries the electrical signal from the inner ear to the brain.  

There is an explanation video available .