What Is the Auditory Nerve?

The sense of sound characteristics produced by the auditory organs under the action of sound waves. A suitable stimulus is sound waves. Sound waves are the periodic compression and thinning of air triggered by the vibration of an object. The hearing organ is the ear. The ear is divided into three parts: the outer ear, the middle ear and the inner ear. Auditory receptors are Coty's organs composed of auditory cells on the basement membrane in the inner cochlea. The sound emitted by the object is transmitted through the air, through the conduction system of the outer ear, middle ear and inner ear, causing vibrations of the cochlea lymphatic fluid and basement membrane fibers, and thereby arousing the excitement of auditory cells and generating nerve impulses. Impulses travel along the auditory nerves to the medial geniculate body of the thalamus, exchange neurons and enter the auditory region of the cerebral cortex (superior temporal gyrus) to produce hearing. Sound waves have frequency, amplitude, and waveform characteristics, which determine the three different effects of pitch (tone), sound (intensity), and timbre (sound quality) of hearing. An important feature of human hearing is the wide dynamic range of the auditory sensory threshold. With regard to the parameter of the vibration frequency of sound waves, the pure sound that humans can hear is between 16 Hz and 20,000 Hz. The sensation of sound wave amplitude (sound intensity) can be as low as 0 decibels and as high as 120 decibels. Individual hearing thresholds vary widely and are affected by various factors such as age and environment. People who are more sensitive to music can distinguish between 20 and 30 middle notes between two adjacent keys of the piano. Humans and animals can distinguish the nature of the sounding object and its direction and distance based on the sound of the object and its changes.

The sense of sound characteristics produced by the auditory organs under the action of sound waves. A suitable stimulus is sound waves. Sound waves are the periodic compression and thinning of air triggered by the vibration of an object. The hearing organ is the ear. The ear is divided into three parts: the outer ear, the middle ear and the inner ear. Auditory receptors are Coty's organs composed of auditory cells on the basement membrane in the inner cochlea. The sound emitted by the object is transmitted through the air, through the conduction system of the outer ear, middle ear and inner ear, causing vibrations of the cochlea lymphatic fluid and basement membrane fibers, and thereby arousing the excitement of auditory cells and generating nerve impulses. Impulses travel along the auditory nerves to the medial geniculate body of the thalamus, exchange neurons and enter the auditory region of the cerebral cortex (superior temporal gyrus) to produce hearing. Sound waves have frequency, amplitude, and waveform characteristics, which determine the three different effects of pitch (tone), sound (intensity), and timbre (sound quality) of hearing. An important feature of human hearing is the wide dynamic range of the auditory sensory threshold. With regard to the parameter of the vibration frequency of sound waves, the pure sound that humans can hear is between 16 Hz and 20,000 Hz. The sensation of sound wave amplitude (sound intensity) can be as low as 0 decibels and as high as 120 decibels. Individual hearing thresholds vary widely and are affected by various factors such as age and environment. People who are more sensitive to music can distinguish between 20 and 30 middle notes between two adjacent keys of the piano. Humans and animals can distinguish the nature of the sounding object and its direction and distance based on the sound of the object and its changes.

Chinese name

Hearing

Foreign name

auditory sensation

Hearing I. Overview:

The perception of sound through the perception and analysis of the auditory system. External sound waves enter the external ear canal, causing the eardrum to vibrate. The vibration frequency of the eardrum is consistent with the frequency of sound waves, and the amplitude is determined by the strength of the sound waves. When the tympanic membrane vibrates in the internal and external directions, the three ossicles pass through the sacrum floor, which vibrates against the vestibular window, causing the inner ear vestibular external lymph fluid to vibrate. The vestibular membrane, the endolymphatic lymph, the basement membrane, the extratympanic lymph, and the round window membrane were vibrated one after another. The vibration of the basement membrane makes the relative position of the hair cells of the spiral device and the cover membrane constantly change, causing the hair cells to emit nerve impulses and causing the cochlear nerve fibers to generate action potentials. It travels to the medulla oblongata, then through the midbrain to the medial geniculate body, and finally to the temporal lobe of the cerebral cortex, forming hearing. The frequency of the sound is the level of the tone. The range that a normal person can feel is 20 to 20,000 Hz. The intensity of the sound is the loudness. The weakest sound that a person can feel is about 0.0002 dyne / cm2, which is stronger than it. One million times the sound, people can still tolerate. People have a high ability to discern the tone frequency and intensity. Hearing has physiological phenomena such as adaptation and fatigue. Hearing loss caused by damage to or damage to the tympanic membrane or ossicular chain of the middle ear is called conductive deafness. Inner ear spiral organs, snail nerves and central nervous system lesions, called neurological deafness. Under normal circumstances, sound waves are mainly conducted through the air, and patients with dysfunction of the ossicular chain can also make the sound waves pass to the inner ear through the direct contact of the sounding object with the skull, causing hearing. This method can be used to distinguish between conductive deafness and neurological deafness.

Hearing is accomplished by the joint activities of the ear, auditory nerve, and auditory center. The ear is the peripheral sensory organ of hearing, consisting of the outer ear, middle ear, and inner cochlea; the outer and middle ears are the sound transmission system, and the inner ear is the sensory system.

The appropriate stimulus for the human ear is sonic vibration of 16 to 20,000 times per second. The vibration of the sound source causes the eardrum to vibrate, which is transmitted to the elliptical window (vestibular window) through the leverage of the auditory ossicles, which in turn causes the external lymphatic vibration of the inner ear, that is, the sound waves enter the inner ear. In this way, the original air conduction with large amplitude and weak vibration force becomes liquid transmission with small amplitude and strong vibration force. As a result, it not only enhances the sensitivity of hearing, but also protects the inner ear.

The vibration of the inner ear and outer lymph causes the inner lymph and basement membrane in the membrane spiral to vibrate, thereby exciting the hair cells on the screw. The spiral device and the hair cells contained therein are real sound-sensing devices. The auditory nerve fibers are distributed in the basement membrane below the hair cells. The mechanical energy finally transforms into nerve impulses here, that is, the excitement of the hair cells causes the auditory nerve fibers to produce impulses, and It is transmitted to the auditory center of the cortex via the auditory nerve fibers, causing hearing. On the other hand, when the tympanic membrane vibrates, the air vibration elliptical window in the middle ear drum can also cause the basement membrane to vibrate, but this conduction pathway is not important under normal circumstances, and it only shows its effect when the ossicles are damaged.

In addition, in addition to the above-mentioned air conduction through the outer and middle ears, sound waves can also be transmitted to the inner ear through bone conduction, that is, the vibration of the skull through the vibration of the skull causes vibrations in the cochlea lymph in the bone of the temporal bone to produce hearing, which is normal. Inferior bone conduction is even less important.