Briefly describe the route by which sound waves enter the inner ear

Sound generally enters the inner ear through air conduction, which is the main way we perceive sound; Another secondary route is through cranial conduction.

The vibrations of the sound waves are collected by the auricle and pass through the external auditory canal to the tympanic membrane, causing mechanical vibrations of the tympanic membrane and the ossicular chain, which transmit the stapes foot plate through the vestibular window to the external lymph of the inner ear. This pathway is called air conduction

conduction), referred to as air conduction. After the sound wave is transmitted to the lymph outside the inner ear, it is transformed into liquid wave vibration, which causes the basement membrane to vibrate, and the spiral hair cells located on the basement membrane bend the stecilia, causing the hair cell electrical activity, and the hair cell releases neurotransmitters to stimulate the axon terminals of the spiral ganglion cells, generating axonal action potentials. Nerve impulses travel along the brainstem auditory pathway to the auditory cortex center in the temporal lobes of the brain.

In addition, the air in the tympanic chamber can also vibrate through the round window membrane to produce a change in the lymphatic pressure of the inner ear, causing the basement membrane to vibrate. This pathway is secondary in normal people and only occurs when there is an obstruction or disruption of the normal conduction through the vestibular window, such as a large perforation of the tympanic membrane, or a disruption or fixation of the ossicular chain.

Structures that increase sound pressure during the passage of sound waves to the inner ear include the ossicular chain, the external auditory canal, and the tympanic membrane.

Sound is transmitted to the inner ear through air conduction and skull conduction. Generally based on air conduction, sound produces sound waves, collected by the auricle, reaches the tympanic membrane through the external auditory canal, and is transmitted from the vestibular window to the inner ear epilymph through the lever of the ossicular chain, causing the basement membrane to vibrate, generating nerve impulses, and passing through the auditory nerve to the auditory center to produce hearing.

Physiology of the ear

The ear can be divided into three parts: the outer ear, the middle ear, and the inner ear, which connect the auditory nerve to the brain and constitute the human auditory system.

The structure of the ear passes from the pinna of the outer ear into the external auditory canal, followed by the middle eardrum (tympanic membrane); There are three ossicles in the middle ear cavity, namely the hammer bone, the incus and the stapes. The stapes touch the foramen ovale of the inner ear, from which sound travels to the inner ear. The structure of the inner ear can be divided into two main parts.

The cochlear part is responsible for hearing and is integrated into the cochlear nerve, the vestibular semicircular canal part is responsible for balance, and the semicircular canal part is integrated into the vestibular nerve, which in turn combines to form the vestibular nerve of the cochlea, which is the eighth cranial nerve, which then enters the auditory nucleus of the brainstem and then reaches the auditory center of the brain. The main area of the auditory center is in the temporal lobe of the brain. Therefore, the ear is only used to transmit sound, and ultimately the brain still has to listen to sound.

In addition to air, elastic media such as water, metal, and wood are also capable of transmitting sound waves, and they are all good mediums for sound waves. In a vacuum, because there is no elastic medium, sound waves cannot propagate.

When two or more sound waves meet, they add or subtract from each other, influencing each other to superimpose, a phenomenon known as wave interference. If their peaks and troughs are exactly in phase, they reinforce each other and therefore produce a waveform with a higher amplitude than any single waveform. If the peaks and troughs of the two waveforms are completely out of phase, they cancel each other out, resulting in no waveform at all.

Sound waves External auditory canal tympanic membrane Osicular chain (malleus, incus, stapes) Vestibular window Vestibular extra-lymph Vestibular membrane Intracochlear lymph Spiral membrane (basement membrane) Spiral apparatus (generating nerve impulses) Cochlear nerve Cerebral cortex auditory center extravestibular lymph Cochlear scale extratympanic lymph Second tympanic membrane (protruding into the tympanic chamber, buffering the vibration of lymph) Cerebral cortex auditory center.

Sound waves travel through air and other mediums, from far to near, and forward.

This requires professionals to understand the people of the Northeast in detail, and you will need professional personnel who will give you specific explanations and detailed instructions.

Outside sound waves enter the external auditory canal, causing the eardrum to vibrate. The vibration frequency of the eardrum is the same as the frequency of sound waves, and the amplitude is determined by the intensity of the sound waves. When the tympanic membrane vibrates in the internal and external directions, the stapes floor against the vestibular window vibrates through the transmission of the three ossicles, causing the lymph fluid outside the vestibular step of the inner ear to vibrate.

The vestibular membrane, intracochlotal lymph, basement membrane, extratympanic lymph, and round window membrane vibrate successively.

The vibration of the basement membrane causes the relative position of the hair cells of the spiral to change continuously with the operculum membrane, causing the hair cells to send out nerve impulses, causing the cochlear nerve fibers to produce action potentials. It travels to the medulla oblongata, then through the hypothalamus of the midbrain to the medial geniculate body, and finally to the temporal lobe of the cerebral cortex, where hearing is formed.

Auricular (collecting sound waves) - causing tympanic membrane vibrations - ossicular chains (malleus, incus and stapes) vibrations - inner auditory canal - cochlear auditory receptors.

Sound begins with the vibrations of air particles, such as guitar strings, human vocal cords, or speaker paper cones. Together, these vibrations appear as pushing neighboring air molecules while slightly increasing air pressure. The air molecules under pressure then push the surrounding air molecules, which in turn push the next group of molecules.

Sound waves are transmitted to the inner ear through the external auditory canal, eardrum, and ossicles, which excite the sensory organs of the inner ear (Coti's organs), and convert sound energy into nerve impulses, which then pass through the auditory nerve and enter the center to produce hearing. When these pressure wave changes reach the human ear, they vibrate the nerve endings in the ear, and we hear these vibrations as sounds.

Check the answer analysis [Correct Answer].

1.Air conduction: Air conduction is the main pathway for the acoustic celery wave to enter the inner ear. In addition, vibrations of the tympanic membrane can cause air inside the tympanic to vibrate, which then passes through the round window membrane to the inner ear.

2 Bone conduction: Bone conduction has low sensitivity and has little effect on normal hearing formation, but when the tympanic membrane or middle ear lesion causes significant impairment of air conduction, bone conduction is not affected, and even relatively strengthened.

a.The outer ear has a tympanic membrane, an auditory bone chain, a vestibular window, and an inner ear.

b.The outer ear has an eardrum, an auditory bone chain, a feast, a snail window, and an inner ear.

c.Outer ear, one tympanic membrane, one tympanic air, one worm window + inner ear.

d.Skull - Intracochlear lymph.

Correct answer: The outer ear is a tympanic membrane and an ossicular chain is a vestibular window and an inner ear.