How do we hear?
Many of us are sometimes interested in a simple physiological question regarding how we hear. Let's take a look at what our organ of hearing consists of and how its work comes about.
First of all, we note that the auditory analyzer has four parts:
- Outer ear. These include the auditory drive, the auricle, and the eardrum. The latter serves to isolate the inner end of the auditory wire from the environment. As for the ear canal, it has a completely curved shape with a length of about 2.5 centimeters. There are glands on the surface of the auditory canal, and it is also covered with hairs. It is these glands and secrete earwax, which we clean in the morning. Also, the ear canal is necessary to maintain the necessary humidity and temperature inside the ear.
- Middle ear. That component of the auditory analyzer, which is located behind the eardrum and is filled with air, is called the middle ear. It connects with the help of the Eustachian tube with the nasopharynx. The Eustachian tube is a rather narrow cartilaginous canal, which is normally closed.When we make swallowing movements, it opens and air enters through the cavity. Inside the middle ear are three small auditory ossicles: the anvil, the malleus, and the stirrup. The malleus with one end connects to the stirrup, and it is already molded in the inner ear. Under the influence of sounds, the eardrum is in constant motion, and the auditory ossicles already transmit its vibrations further inwards. It is one of the most important elements that needs to be studied when considering which structure of a person’s ear
- Inner ear. In this part of the auditory ensemble there are several structures at once, however, only one of them controls the hearing - the cochlea. She received this name because of its spiral shape. It has three channels that are filled with lymphatic fluids. On the average channel, the liquid is significantly different in composition from the rest. The organ that is responsible for hearing is called the Corti organ and is located in the middle canal. It consists of several thousand hairs that capture the vibrations created by the fluid moving through the channel. It also generates electrical impulses that are then transmitted to the cerebral cortex. A certain hair cell responds to a particular kind of sound.If it happens that the hair cell dies, then the person stops perceiving this or that sound. Also, in order to understand how a person hears, one should also consider the auditory pathways.
They are a collection of fibers that conduct nerve impulses from the cochlea itself to the auditory centers of your head. It is thanks to the ways our brain perceives one or another sound. There are auditory centers in the temporal lobes of the brain. The sound that passes through the outer ear to the brain lasts about ten milliseconds.
How do we perceive sound
The human ear processes sounds from the environment into special mechanical vibrations, which then convert the movements of the fluid in the cochlea into electrical impulses. They follow the paths of the central auditory system to the temporal parts of the brain, in order to be recognized and processed. Now the intermediate nodes and the brain itself extracts some information about the volume and pitch of the sound, as well as other characteristics, such as sound capture time, sound direction, and others.Thus, the brain can perceive the received information from each ear in turn or together, receiving a single sensation.
It is known that inside our ear are stored some "patterns" of already studied sounds that our brain has recognized. They help the brain to properly sort and determine the source of information. If the sound is reduced, then the brain accordingly begins to receive incorrect information, which can lead to a misinterpretation of sounds. But not only sounds can be distorted, over time the brain also undergoes an incorrect interpretation of certain sounds. The result may be an incorrect human response or incorrect interpretation of information. In order to properly hear and reliably interpret what we heard, we need the synchronous work of both the brain and the auditory analyzer. That is why it can be noted that a person hears not only the ears, but also the brain.
Thus, the structure of the human ear is quite complicated. Only the coordinated work of all parts of the organ of hearing and the brain will allow us to correctly understand and interpret what we heard.