Human ear:
Working of the human ear:
The outer ear is called ‘pinna’. It collects the sound from the surroundings. The auditory canal passes this sound to a thin membrane called the eardrum or tympanic membrane. When a compression or rarefaction of the medium reaches the eardrum, it moves inward or outward. In this way, the eardrum vibrates. These vibrations are amplified several times by three bones- the hammer, anvil, and stirrup in the middle ear. The middle ear transmits the amplified pressure variations to the inner ear. The cochlea converts these variations into the electrical signals in the inner ear. These signals are sent to the brain via the auditory nerve. The brain interprets them as sound.