A newborn baby can sleep even in a loud noise, and this does not bother him at all. But at the same time, parents wonder if the child hears at all. In this article, we will consider the features of hearing in newborns, as well as methods for determining it at home.
Development of auditory function
You might be surprised, but to hear babies begin in the womb... The hearing organs are formed early - at the 5th week of pregnancy, the rudiments of future ears, or rather the inner ear, are formed. At 7 weeks, the middle ear is formed, and then the auricle. The auricles of the fetus become hard only shortly before birth.
The inner ear, which is important for gaining the ability to hear, completes its formation at about 19 weeks. And the auricle after birth continues to remain rather soft, the auditory meatus is narrow, and this will correct itself only by the first year of life.
Babies begin to pick up the first sounds in their mother's belly after 14 weeks.... But while these sounds are more reminiscent of the hearing of a reptile, the fetus picks up the vibrations that accompany sound waves. As the formation of the inner ear completes and the labyrinth hardens, the ability to hear better appears. This happens after 20 weeks, by the 26th week of pregnancy, the baby in the stomach hears almost as we do, but with the amendment that it is still in the aquatic environment.
He hears her mother's heart beating and blood flowing through the vessels, how her intestines work. He hears her voice and quickly gets used to it. Sounds from the outside begin to interest the baby only in the last weeks of pregnancy. The child hears the music that sounds in the mother's headphones, but only if the headphones are put on directly on the stomach. If they are on the mother's ears, the child cannot hear the sounds.
A baby is born hearing. If a newborn's vision is very imperfect, and the baby perceives only blurry fuzzy spots, then everything is fine with his hearing.
Of course, provided that in the process of laying and developing the hearing organs in the prenatal period of development, errors and problems did not arise that could affect the state of hearing.
Screening after birth
In the first days of life (usually after the second day) in the maternity hospital, all newborns undergo a special study - a test of hearing abilities or audioscreening. A special apparatus records the response of hair cells to sound stimuli. For the second time, the examination as part of the screening is recommended to be carried out at the age of 1 month, 3 months, in six months.
It is difficult to say how reliable such a study is. If it gave the most accurate data, it would be possible to diagnose hearing pathologies up to a year.
In the meantime, most cases of minor sensorineural hearing loss and unilateral hearing loss or deafness (if one ear cannot hear) are detected much later. That is, a child who has successfully passed the audio screening may well be hard of hearing.
The maternity hospital uses the method of delayed otoacoustic emission... A portable device with a small, thin, flexible probe is called an audiometer. One part of the probe fits into the baby's ear. The device directs sounds into the ear along the probe. The hair cells in the inner ear trap them and strengthen them if the baby hears. If not, then the hair cells do not receive the signal, there is no impulse. For more accurate results, it is considered optimal if the baby is fed and asleep.
In the discharge from the hospital, if you look closely, you can find the following designations: D (+) = S (+). This means that the screening was successful in both the right and left ear. He hears.
If instead of pluses there is a minus, the screening showed no reaction of the hair cells, and therefore the child will definitely be assigned an additional examination.
Screening for premature babies has its own nuances. An acoustic examination is carried out for them not on the second day, taking into account the immaturity of all organs and systems, including the hearing organs, but on any day after 2-4 weeks of life.
At risk for possible pathologies are children born to deaf or hearing impaired parents, as well as children who were born from pregnancy, during which a woman had been ill with infectious viral diseases, especially if this happened in the early stages.
How to check at home?
All parents of newborns, one way or another, try to independently understand how the baby sees and hears. At home, a method such as observing the child's reaction to sounds will help.... The behavioral method is only approximate, inaccurate, because if some deviations are found, it cannot show how significant the hearing loss is, what caused it. But this is not required from a home check.
Parents can test their hearing on their own in order to consult a doctor in case of dubious or unsatisfactory results. No need to wait for the child to grow up... For normal mental development and speech development, it is important to hear, and therefore hearing correction is also possible in infancy: children are fitted with hearing aids (ear correctors), operations are performed to restore the auricle if there are defects in the outer ear.
There are many ways to help a child, but help will be more useful if it is provided as early as possible.
If the child is already one month old, you can try the behavioral method. It is based on the baby's specific reactions to sounds. It is important that the child is at rest, dry and well-fed..
First, make different sounds from the right ear, and then from the left. Start by clapping your hands from a distance of about half a meter. Then check how your baby perceives quieter sounds, for example, the sound of a rattle (choose a toy with an initially low sound). High frequencies can be tested with semolina, which mom can put in an empty metal jar. Shake such a jar not far from the ear - the high-frequency sound of cereals can be caught by the baby only at close range.
How to understand that a child perceives a particular sound:
- he is enlivened to the sound by the synchronized waves of his arms and legs;
- he freezes and tries to find the source of the strange sound;
- the baby opens his eyes wide, changes his facial expression;
- the crumbs change the frequency and depth of breathing.
Home hearing tests are never done on children who are sick, have colic or have a tooth cutif the baby is hungry or did not get enough sleep. Any discomfort a baby feels increases the likelihood of an inappropriate behavioral response to sounds.
In the first month of life, children almost do not distinguish low frequencies, for them the high-frequency range is more familiar. If the tests are carried out on children from 3 months and older, then such an important feature as turning the head towards the sound source is added to the list of reactions.
A hearing test method based on the reproduction of different sounds in frequency is called the Kalmyko methodhowl. For such a check, you will need three plastic containers, which are suggested to be filled by a third with semolina, buckwheat, and peas... These will be high, medium and low frequencies. To check, you will have to involve dad or grandmother as assistants. While one distracts the child's attention with a bright toy, an unusual object, the second one half a meter from the right, and then from the left ear shakes the can. They start with semolina (that is, with high-frequency sounds), then take buckwheat, and last of all - peas. Between changing cans, take a break for a couple of minutes.
The test is considered successful if the child, albeit without being distracted from the toy, reacts (even for a short time) to the sound of cereals in cans... He can freeze for a second, turn his head and look at the can, start looking for the source of the sound with his eyes, change his facial expression. If there is no reaction at all, the child should be shown to the ENT and audiologist.
Possible problems
Hearing problems in newborns and babies can be different. The reason for the lack of hearing in a severe case lies in the anomalies of the auditory nerve or the auditory center of the brain, and maybe the result of mechanical damage - the mother cleaned the child's ears with ear sticks and damaged the membrane.
In the second case, sometimes it is quite enough to clear the auditory canals, drip drops, and everything goes away. But more often in the case of hearing loss, medications are ineffective, especially if the hearing loss is congenital. The forecasts, alas, are disappointing. It is impossible to cure the disease, but you can significantly improve the quality of a child's life, give him a chance to develop normally, learn to speak, and adapt in society. Audiologists and hearing aids will help with this.
Correctly selected hearing aids, cochlear implantation surgery can give the child the opportunity to hear. Reviews of such methods are good, because they give hearing impaired children real chances for a normal and fulfilling life.
A specialist tells about the early diagnosis of hearing impairment in the video below.
