Science has come close to unraveling the reasons why some people hate noise – it’s all in the brain. About the problem of misophonia and ways to solve it - in the material of Izvestia.
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Scientists from Newcastle University (UK) found that patients suffering from so-called selective sound sensitivity have increased connections between the “auditory” region of the brain and the area responsible for movement and facial expressions (motor control areas in the cortex). Researchers consider the extreme reaction of people suffering from misophonia to irritating sounds to be a consequence of these hypersensitive contacts.
Misophonia, also known as selective sound sensitivity syndrome, is associated with aversion to a certain range of sounds - someone else's slurping, heavy breathing, swallowing, gargling. These and similar sounds cause significant discomfort to people suffering from the disorder. American scientists believe that from 6 to 20% of the world's population are susceptible to misophonia to one degree or another. By the way, there are similar disorders that differ in nature - these are hyperacusis (intolerance to sound levels that are acceptable to others) and phonophobia (hatred of loud sounds).
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A study report published in the Journal of Neuroscience states that 33 volunteers were tested using f-MRI scans. Responses to stimuli were also compared in 42 patients with misophonia and a control group.
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Simply put, the basis for irritation is not a reaction to the sounds themselves, but the fact that certain noises cause activity in the area of the brain responsible for the movement of the jaw, larynx and other organs.
“We assume that in misophonia, the stimulus sound activates the motor area,” explained neuroscientist Subinder Kumar. Thus, a person feels a hostile “invasion of sounds.” Some patients manage to cope with symptoms by imitating an action, the sound of which is annoying. This helps restore a sense of control to the patient, Kumar says. According to scientists, the study proves a “neurobiological model” of the disease. According to this theory, the mechanism of misophonia is associated with increased activity in certain areas of the brain.
Fu1 sounds
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Kumar's earlier research confirmed that misophonics have atypical connections between the frontal lobe and the anterior insular cortex (involved in emotional processing). During the tests, they placed the subjects in an MRI machine and alternately played three types of sounds - neutral (for example, the sound of rain), alarming (a child crying) and sounds characteristic of eating. Misophonia sufferers reacted painfully precisely to the sounds of the third category - the activity of both studied zones at the time of reproduction of slurping and swallowing was maximum. Plus, at these moments, the experimental subjects’ heart rate increased and sweating increased. However, researchers were not then able to unambiguously answer the question of whether misophonia could be a consequence of such a brain abnormality, according to a scientific publication on the Current Biology portal.
Evolution
Studies have shown that people perceive sounds of a certain frequency as unpleasant. Human hearing is especially sensitive to sounds between 2000 and 5000 Hz. In this interval there are many sounds that make many people feel uncomfortable - the creaking of polystyrene foam, the scratching of a knife on a plate, screams.
The way we perceive sounds in this range was ingrained in us by evolution thousands of years ago. The hearing aid helped detect danger much faster than other senses, so people still subconsciously react sharply to sounds that resemble the screams of predators or the creaking of their claws. The unpleasant sensations we are experiencing now and the desire to hide are the instinct of self-preservation inherent in primitive man. We did not get rid of it because humans as a species ceased to depend on living nature quite recently - from the point of view of evolution.
Special opinion
But there are alternative theories that explain the mechanism of deviation: “psychophysiological model”, “phantom model” and “misophonia as a conditioned aversive reflex disorder”.
The phantom model was proposed by neuroscientists from the USA Pavel and Margaret Yastrebov. According to their version, deviations in neural activity in the auditory neural pathways are to blame. Moreover, the same disorder is characteristic of tinnitus (tinnitus) and hyperacusis.
Supporters of the “psychophysiological model” believe that the issue is in the autonomic nervous system, and have experimentally established a connection between misophonia and skin conductivity. And according to the “reflex” version, misophonia is associated with physical and emotional reflex reactions. One of the authors of this model, American researcher Thomas Dozier, believes that it is based on repeated unpleasant actions, which over time cause negative emotional and autonomic (increased heart rate, sweating) reactions. In the future, even fragmentary returns to negative experiences cause a violent reaction.
Fu2 sounds
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According to psychologist Eldar Osipov, the analysis presented in studies on the topic of selective sound sensitivity shows only the conjugation of two phenomena: mesophonia and some morphological features of the brain. That is, it does not reliably follow from these studies what is the cause and what is the effect.
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Mechanism of occurrence
The human body is equipped with powerful compensatory systems. When the outer, middle and inner ear are damaged, the amount of information that enters the brain is significantly reduced.
The auditory system is forced to compensate for this disorder by strengthening other auditory areas.
Loud noise intolerance occurs when the balance between amplification and inhibition mechanisms in the auditory areas is disturbed. In this case, all processes are reconfigured and the excitation threshold is reduced.
As a consequence of this, sound signals that are normally perceived in a normal state cause severe discomfort and pain.
In such conditions it is very difficult to lead a normal life. A person with such a disorder has to limit communication with others and give up many professions.
How to live with it
“In psychological practice, in particular in psychotherapy, there are approaches that explain the phenomenon of misophonia through neurotic (psychological) causes, and their nature comes down to a traumatic event,” Osipov told Izvestia. - Actually, like all psychological problems that are dealt with by practical psychology and psychotherapy. In psychological practice, they work with misophonia as if it were a trauma, and often successfully, but not always. Since the nature of this phenomenon is still not fully understood.
In his opinion, every person has misophonia to a greater or lesser extent and normally its manifestations are invisible.
— The problem becomes acute and noticeable when it causes painful emotional reactions. There are observations from which it follows that most often misophonia begins to develop between the ages of 7 and 10, and this is consistent with both the psychological approach to explaining the phenomenon and the physiological one.
Treatment of painful sound perception
As a rule, patients turn to an otolaryngologist with complaints of a painful reaction to sounds. Usually the same specialist determines the presence of a disorder and the need for medical assistance. To get rid of pain in relation to sounds, the most important thing is to accurately identify and eliminate the cause. In the process of treating hyperacusis and misophonia, the patient may need consultations or even medical assistance from an audiologist and neurologist. That is why, in case of painful perception of sounds, it is necessary to go to the clinic, and not try to get rid of the disease on your own.
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Hyperacusis
A hearing disorder in which there is increased sensitivity to sounds at only certain frequencies and volume ranges is called hyperacusis.
There are three types of noise that are particularly difficult to tolerate with hyperacusis:
- unexpected sharp sounds - the ringing of an alarm clock, a doorbell, the sound of a telephone, the knock of a fork or spoon on a plate, a sharp whistle, a cough;
- monotonous high-frequency sounds - the noise of an air conditioner, drill, generator, food processors and other equipment;
- several simultaneous sources of sounds of different volumes - a sports arena, a train station, a supermarket, a theater and other crowded public places.
But if the frequency of sounds changes, then anxiety does not arise.
There are people who feel discomfort from quieter sounds that most people do not pay attention to. Irritations are caused by: quiet tapping on a hard surface, cracking of knuckles, rustling paper, prolonged whining or meowing, sounds of conversations.
How to understand that a child or adult is experiencing hyperacusis
Sensitivity worsens when the patient is in a very noisy or crowded public space, transport, or at active events. When the hearing organs are irritated by unpleasant noise, a person begins to perceive the speech of others much worse.
Adults, when experiencing discomfort, try to avoid irritating sounds: close windows or doors tightly, listen to music or TV. Self-control is very important for adults, therefore, unnatural behavior cannot always be associated with the manifestation of hyperacusis. Sometimes a person himself does not understand that he is sick.
It can be very difficult to diagnose hyperacusis in young children. They cover their ears with their hands, cry, and try to hide. Often a child avoids certain rooms or activities for reasons unknown to parents and others. Particularly severe discomfort can be caused by a categorical refusal to go to kindergarten, school, sports clubs or music classes.
Nervous system diseases
There are a lot of them! This includes multiple sclerosis, meningitis, epilepsy, and a consequence of age-related changes (such as Parkinson's disease)... Dozens of diagnoses, many of which are very serious, but they still need to be made. Noise, humming and whistling in the ears are therefore important symptoms. If they bother you or your loved ones, and the therapist or other specialist to whom you turned for help “waves it off”, saying that it’s tinnitus, a sound for no reason... perhaps you should first look for a more meticulous doctor. There is always time to decide that the sounds come from nowhere and are harmless.
By the way, frequent stress and overwork lead to problems with the nervous system. Maybe before you get an appointment, you should try to at least get some rest? Take a time out, be quiet and in nature. If the intrusive sounds disappear at this time, you are on the right track. Stress less and rest more. You can ask your doctor to prescribe sedatives, but this is not necessary.
The phenomenon of accelerated rise in volume
In everyday life, there are often sound stimuli whose intensity far exceeds the threshold of audibility, in particular the sounds of spoken language. Some pathological changes in the receptors of the diseased ear, such as sensorineural hearing loss, cause increased sensitivity to loud noises. This condition is called FUNG - the phenomenon of accelerating the increase in volume. It often occurs with disorders of the peripheral zone of hair cells of the auditory cochlea.
With this disorder, the amplification of sound signals above the threshold is felt by the person as clearly as with normal hearing; a process of accelerated increase in volume occurs. With unilateral hearing loss, the perception of loudness in the pathological and healthy ears is equalized. In the case of bilateral lesions, the Si-Si test is used to diagnose this phenomenon, identifying the threshold of discomfort and the differential threshold for the perception of sound power (Luscher test).
