The human ear is composed of the outer ear, the middle ear and the inner ear. The human ear has the function of producing hearing and balance. The normal human ear can distinguish about 400,000 different sounds, which are so small that they can only make the eardrum move by one tenth of the diameter of the hydrogen molecule.
When the sound is emitted, the surrounding air molecules emit a series of vibrations, which are sound waves that propagate outward from the sound source. When the sound reaches the outer ear, the sound is transmitted to the external auditory canal through the sound collection of the auricle and reaches the tympanic membrane. The tympanic membrane is the dividing line between the outer ear and the middle ear, and the thickness is as thin as paper, but it is very strong. When a sound wave hits the tympanic membrane, it causes vibration of the tympanic membrane.
In the middle ear cavity behind the tympanic membrane, there are three interconnected ossicles. Each ossicle is only the size of a rice grain and is the smallest bone in the human body. Their names come from their shapes. Next to the tympanic membrane are the humerus (like the iron scorpion), followed by the anvil (like the anvil) and finally the shin (like the horse's owl). When the sound wave vibrates the tympanic membrane, the ossicle is also vibrated. The three listening bones actually form a lever system that amplifies the sound and transmits it to the inner ear.
The last tibia in the three ossicles is attached to a tiny membrane called the oval window. The oval window is the portal of the inner ear, and the inner ear has a specialized organ, the cochlea. When the tibia vibrates, the oval window also vibrates. On the other side of the oval window is a cochlear tube filled with fluid. When the oval window is vibrated, the liquid also begins to flow. There are thousands of hair cells in the cochlea, and they have tiny cilia at the top. When the liquid flows, the cilia of these cells are impacted. After a series of bioelectrical changes, the hair cells convert the sound signals into bioelectrical signals that are transmitted to the brain through the auditory nerve. The brain then processes and integrates the delivered information to produce hearing.
In addition, the inner ear contains a very important organ - semicircular canal. The semi-regular tube is composed of three small rings that are perpendicular to each other, which is responsible for the balance of the three-dimensional space of the head. When the semicircular canal is defective, symptoms of dizziness may occur. Hearing is a necessary communication channel for human social life. However, the most important thing is that hearing makes us feel the environment and create a sense of security and participation. Hearing is important for health.
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