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Hearing is the process by which humans use their ears to detect and perceive sounds. Ears are important for hearing and for controlling a sense of position and balance. Each ear is divided into three sections:
The outer ear.
The middle ear.
The inner ear.
The middle and inner parts of the ear are located in hollow spaces on either side of the head within the temporal bones of the skull.
To hear sound, the ear has to do three basic things:
Direct the sound waves into the hearing part of the ear.
Sense the fluctuations in air pressure.
Translate these fluctuations into an electrical signal that the brain can understand.
The outer ear
The external part of the ear consists of the pinna and ear lobe.
The pinna or ear shell is the shell-like part of the external ear, and it is made of cartilage and skin. The pinna directs sound waves from the outside into the external auditory canal (ear canal), which in turn channels sound waves to the tympanic membrane (known as the eardrum), causing it to vibrate. The tympanic membrane is a thin, semi-transparent, flexible membrane that separates the outer and middle ear.
The outer ear functions to collect sound (acoustic energy), and funnel it to the eardrum (tympanic membrane).
The Eustachian tube
The Eustachian tube is a narrow tube that connects the middle ear to the back of the nose and throat. During swallowing, the Eustachian tube opens up to allow air into the middle ear, so that air pressure on either side of the tympanic membrane is the same. In some situations when there is a sudden change in air pressure (for example – during take off and landing in a plane), the pressure in the middle ear is not the same as the outside air pressure. This can make the eardrum bulge or retract and less able to transmit vibrations, causing temporary hearing problems. By swallowing or “popping” the ears, the pressure can again be equalised.
Chepj answered the question on January 26, 2018 at 14:22
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