News and Highlights

Sounds and words are processed in the brain separately

Auditory and speech processing occur in the brain in parallel and simultaneously, according to a new study that contradicts a long-held theory that the brain processes acoustic information first and then transforms it into linguistic information.

The finding is published in the journal Cell and, specifically, neuroscientists from the University of California (USA) have discovered a new pathway in the human brain that processes the sounds of language.

These, upon reaching the ears, are converted into electrical signals by the cochlea and sent to a region of the brain called the auditory cortex, in the temporal lobe.

For decades, scientists have thought that speech processing in the auditory cortex occurred in series, similar to an assembly line in a factory, explains a statement from the publication.

It was believed that, in the first place, the primary auditory cortex processed simple acoustic information, such as the frequencies of sounds. Next, an adjacent region, called the superior temporal gyrus, extracted the most important features for speech, such as consonants and vowels, transforming the sounds into meaningful words.

However, the authors of this work point out, this theory has not been directly demonstrated, as it requires highly detailed neurophysiological recordings of the entire auditory cortex with extremely high spatio-temporal resolution.

Edward Chang and his team studied nine participants for seven years who had to undergo brain surgery for medical reasons, such as removing a tumor or locating a seizure focus.

Arrays of small electrodes covering their entire auditory cortex were placed in order to collect neural signals for language and seizure mapping.Participants also agreed to have the recordings analyzed to understand how the auditory cortex processes speech sounds.

"This is the first time that we were able to cover all these areas simultaneously directly from the surface of the brain and analyze the transformation of sounds into words," describes Chang.

When the researchers reproduced phrases and short sentences for the participants, they expected to find a flow of information from the primary auditory cortex to the adjacent superior temporal gyrus, as proposed by the traditional model; if that's the case, the two areas should be activated one after the other.

Surprisingly, they found that some areas in the superior temporal gyrus responded as quickly as the primary auditory cortex when phrases were played, suggesting that both areas began processing acoustic information at the same time.

In addition, the researchers stimulated the primary auditory cortex of the participants with small electrical currents; if speech processing were serial, these stimuli would probably distort the patients' perception of speech.

In contrast, although they experienced stimulus-induced acoustic hallucinations, they were still able to hear and clearly repeat the words spoken to them.

However, when the superior temporal gyrus was stimulated, they reported that they could hear people speak, "but not make out the words."

This evidence suggests that the traditional hierarchy model of speech processing is oversimplified and probably incorrect, according to the scientists, pointing to the possibility that the superior temporal gyrus functions independently - rather than as a next step - from processing in the primary auditory cortex.This parallel nature can give new ideas on how to treat diseases like dyslexia. "Although this is an important step, we still do not understand this parallel auditory system very well; it raises more questions than answers," sums up Chang.

Hearing loss brings with it other ailments

A study reveals that hearing loss contributes to reduced physical activity and the development of other health problems, such as tinnitus and heart disease.

 

According to a US investigation, people with hearing loss suffer from tinnitus and other health problems to a greater extent than those who report normal hearing.

High chances of tinnitus

The study was carried out using data on self-reported hearing loss, that is, indicated by the participants themselves. It found disproportionate rates of tinnitus and heart disease at all levels of hearing loss, but most notably among those who reported having moderate or severe hearing difficulties. As reflected in the study, the probability of the appearance of tinnitus was 8.6 times higher among these people. Furthermore, among the participants who reported having hearing loss, regardless of the level, the probability that they also reported suffering from heart disease was between 3 and 5 times higher.

Participants who reported living with hearing loss were also between 2.5 and 9 times more likely to not be able to perform moderate or intense physical activities on a weekly basis, depending, however, on the degree of their hearing loss.

Of the total of adults who participated in the study, about 1 in 5 claimed to have hearing loss to a greater or lesser degree.

Worse health than the previous year

Participants with moderate hearing loss or with severe hearing difficulties considered that their health had deteriorated from the previous year almost 3 times more than participants with excellent or good hearing.

Information about the study

The aim of the study was to identify the current health status of the adult population with self-reported hearing loss in the US and to compare it with adults with excellent or good hearing in the country.

The study was conducted using 2014 data from the US National Health Interview Survey (NHIS), which is conducted in person at the homes of the participants. On this occasion, a total of 36,697 interviews were conducted based on a questionnaire in order for the participants to report on their hearing ability.

Respondents were grouped into four categories: excellent hearing or good hearing; some difficulty hearing; moderate or very hard of hearing; deafness. The excellent or good hearing group was used as the control group for the other three levels of hearing.

The study, "Health Status of Adults with Hearing Loss in the United States," was published in the journal Audiology Research.

Sources: www.ncbi.nlm.nih.gov and Audiology Research magazine

The weather changes typical of autumn impair hearing health

During the fall our hearing health can be affected. The diseases that we can suffer in the ears are intensified by sudden changes in temperature and the beginning of the rains. The climatic characteristics of this season, with oscillating temperatures, strong wind, humidity, etc. ... increase the risk of contracting colds and viral diseases that can affect the ears and even, in the most severe cases, lead to hearing loss in different degrees. To avoid it and learn to take care of our ears, from Quiero Oír we explain what the most common symptoms and pathologies are and how to prevent them.

As a starting point, those flu and colds whose number begins to increase in autumn cause a high production of mucus that can accumulate in the ears and cause inflammation of the Eustachian tube, affecting our hearing health. As a consequence of the inflammation we will begin to notice a sensation of plugged ears and a slight loss of hearing. In these first moments it is advisable to go to the specialist's consultation, who will assess the suitability of prescribing an adequate treatment to promote the expulsion of mucus and recover the usual level of hearing.

Otitis media, the most common in cold months

On the contrary, if the excess mucus is not eliminated, an infection of the ear canal can occur, an otitis media, the most common in cold months, which manifests itself in the form of pain in the ear, a feeling of plugging, discomfort general and fever in some cases. Based on the chronicity of the infection, the ENT may indicate the administration of oral antibiotics to eliminate it.

Children and the elderly are those who have a greater risk of developing otitis due to their lower defenses. In addition, in the case of children, their Eustachian tube is less developed, which facilitates the access of mucus and bacteria from the nose and throat to the middle ear. Thus, according to data from the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC), 90% of children suffer at least one episode of otitis before the age of five.

Despite them, in people of any age, ear disorders can lead to one of the most common hearing health problems: hearing loss or hearing loss. Successive episodes of otitis or poorly healed infections can cause permanent hearing impairment that begins to affect people's quality of life. Hence the importance of complying with the instructions of the specialists.

Hearing Health Tips in Fall

To avoid catching a cold and take care of your ears so that they do not become infected, we recommend adhering to the following daily application guidelines:

• Avoid sudden changes in temperature, especially when entering or leaving any room. Protects nose and mouth to prevent cold air from entering.
• Wash your hands well to kill germs that can lead to respiratory tract infections. An indication that we have quite assimilated as a result of the pandemic caused by the spread of Covid19.
• Reduce or eliminate tobacco use. Active or passive smoking favors the accumulation of mucus in the throat.
• Maintain proper hygiene of your ears. Dry your ears well after showering and periodically remove excess earwax from the outer area. Always avoid inserting any object that can damage the ear canal, such as cotton buds.
• If you notice that the volume of mucus increases, perform nasal washes with physiological serum or saline solution on a regular basis to promote its expulsion.

For people with hearing aids it is essential to have their devices checked in early fall to ensure their proper function and to get the maximum benefit from their use. This is because during the summer the hearing aids are exposed to high temperatures and humid environments that can reduce their performance. Therefore, despite the fact that the cleaning tasks of these devices are kept up to date, it is recommended that they be reviewed by the hearing care professional.

The importance of wax in the ears of the little ones

False beliefs about the cleanliness of children's ears can lead to infections

The delicacy of the ear canal is unknown to many, as is its care. As a result, most of us incorrectly clean our ears due to popular misconceptions about their hygiene. This poses risks, especially in children, who are more vulnerable because of their young age and that they are still in the development phase. Therefore, it is important to know how to take care of the ears of the little ones so as not to cause any serious problems.

There is a tendency to believe that wax is a sign of poor hygiene, when the reality is that it cleans, protects and lubricates the external auditory canal, acts as a barrier against infection and prevents damage to the eardrum. As a general rule, it is not necessary to extract the wax from children's ears, since when we move the jaws when we speak or chew, the wax comes out of the ear and, with the shower and daily hygiene, it falls off on its own. Only in the case of excess earwax in the outer canal, which is usually shown in symptoms such as itching or discomfort, it is necessary to additionally clean that part of the ear.

In order to improve the care of the ears of the smallest of the house, Joan Francesc Horvath, head of audiology at Optics & University Audiology, lists a series of tips for proper cleaning:

-In the case of excess wax in the outer canal, it is advisable to remove it very carefully with a gauze, without putting anything into the ear.

-Avoid using swabs, fingers or any other object, as these put the wax back into the ear and can scratch the ear canal, produce a plug, create an infection, cause pain and even hearing loss.

-Flee from home remedies such as, for example, pouring a jet of water, which can cause otitis.

-Dry the ears well, although superficially, when leaving the bathroom.

-To go to the ENT every year for reviews. If the child complains of pain or discomfort, a feeling of blockage or any hearing problem, go immediately to the pediatrician or a specialist.

White noise therapy

Learn what white noise therapy is and how it can help you fall asleep or mask the buzzing produced by tinnitus:

What is white noise

When we speak of noise or white sound we refer to a constant and monotonous noise that adds all the frequencies that the human ear captures with the same amplitude or power. This noise masks the ambient sound and causes a state of relaxation and calm for the mind. The sound of a radio or television out of tune, the hissing of air conditioning or raindrops are examples of white noise, in which no frequency stands out above the other.

 

Many relaxation therapies use white noise as science attributes its calming effect to the ability of this noise to mask all other sounds. When white noise is heard, the ear and the cerebral cortex become saturated and the rest of the sounds are not able to pass through this auditory barrier.

Relaxation through white noise

In recent times, the use of white sound has become widespread to help babies and children fall asleep. This technique began to be used in neonatal Intensive Care Units, since it emulated the sounds of the mother's womb and helped babies sleep better.

The ear is the only sense that continues to function while we sleep, so some sounds with altered frequencies can disturb sleep. Using white noise, we can mask ambient noise and avoid startles. But there is a risk, and that is that they can generate a certain dependence at bedtime. In addition, babies stop learning the sounds that are masked and that are also important for their development.

 

The white noise technique to fall asleep is also used in adults who have problems sleeping, since this type of noise is capable of hiding other sounds we live with every day, traffic, neighbors ... White sound has the ability to calm and calm the mind, as they are sounds that the ear gets used to easily and helps to avoid auditory startles during sleep.

Contraindications of white noise

Constant exposure to this type of sound while sleeping causes the hair cells of the ear to remain active during sleep, which is the time when the body carries out regeneration processes, according to neuroscientist Seth Horowitz in the article published by BBC Mundo. Keeping the ear cells active can make it harder for the body to regenerate the area.

White noise as a treatment for tinnitus

People who suffer from tinnitus experience a constant ringing or ringing in their ears. This ailment has no cure at the moment, but white noise is used in some auditory reeducation therapies.

 

White sound is used in patients with tinnitus as training and it is intended to re-educate the auditory pathway. In this way, an attempt is made to reduce the contrast of tinnitus, its sound over silence, and correct the overexcitation of the auditory pathway. With this technique, the person suffering from tinnitus can progressively make the tinnitus go into the background, since the white noise is used in both ears simultaneously without masking the tinnitus.

Source. Kiversal