The results, published in the Journal of Alzheimer’s Disease, point to the need for greater attention to hearing health as a way to prevent dementia.

“Hearing loss is what we call a modifiable risk factor for dementia, including Alzheimer’s, precisely because it can be detected and corrected. By 2050, more than 70% of people with dementia are expected to live in low- and middle-income countries like Brazil.

“That’s why it’s important to have studies that identify our reality and the factors that can be prevented. In addition to the individual burden, there’s also a collective burden.

“There’s no way that Brazil and other low- and middle-income countries can grow old with dementia,” said Claudia Suemoto, professor at the University of São Paulo’s Medical School (FM-USP) and author of the study.

The research was conducted as part of the Longitudinal Study of Adult Health (ELSA-Brazil), which has been monitoring data from 15,000 public servants from six universities and research centers in the country since 2008.

The initiative is funded by the Ministry of Health and the National Council for Scientific and Technological Development (CNPq), linked to the Ministry of Science, Technology and Innovation (MCTI). The audiological assessment and its comparison with the data on cognition collected by ELSA-Brazil were supported by FAPESP.

Mechanisms

Hearing loss usually begins in middle age and is a recognized risk factor for dementia. According to Suemoto, this occurs through two mechanisms. The first is that hearing is an important input pathway for information to the brain.

“It depends on input pathways to deliver a response, along with the knowledge it’s already acquired. However, when a pathway is interrupted, important areas are no longer stimulated, which can accelerate cognitive decline,” she explains.

The second mechanism is behavioral: hearing loss tends to lead to social isolation.

“Almost everyone knows someone older, be it a friend or relative, who doesn’t hear well. To talk to them, you have to speak louder, repeat sentences and they end up being excluded from conversations.

“In a way, it’s so hard for them to hear that they shut themselves out, lose interest and move away. So there’s also the mechanism of social isolation, which is another recognized risk factor for dementia,” she says.

In the study, the participants underwent audiometry tests, an objective measure of hearing quality, three times over the course of the eight-year study.

Tests of memory, language and executive function were carried out during the same period to measure the association between hearing loss and significant cognitive decline. Of the 805 participants, 62 (7.7%) had hearing loss.

After eight years of follow-up, these individuals had faster overall cognitive decline than expected for their age. In addition, specific cognitive tests showed similar but less precise declines in memory, verbal fluency and executive function.

“This shows that it’s important to do an audiometry test because it usually takes a while for people to become aware of their hearing deficit. They start to hear badly, but they don’t realize it and adapt to the new situation.

“But knowing that there’s a loss, it’s possible to correct it with the use of hearing aids. And you also have to remove the stimulus that’s causing the problem,” she warns.

According to the researcher, the main causes of hearing loss in middle age are work-related.

“There are different types of jobs that involve a lot of noise. These people need to wear protective equipment to reduce hearing loss. There’s also the problem of using headphones at too high a volume. All of this is detrimental, so it’s important to get the problem diagnosed,” she adds.

In addition to hearing loss, says the researcher, there are 11 other potential modifiable risk factors for dementia: low education, hypertension, brain damage, diabetes, obesity, alcoholism, smoking, depression, sedentary lifestyle, air pollution and social isolation.

Article originally appeared on Neuroscience News

Eun Seok Kang, M.D., from the Korea University College of Medicine in Seoul, and colleagues conducted a population-based cohort study using the Korean National Health Insurance Service-Senior cohort involving 189,623 participants aged 65 years or older who were categorized as non-SLD or MASLD. The risk for SSNHL and Meniere disease was examined.

The researchers found that compared with the non-SLD group, participants with MASLD had higher metabolic dysfunction markers, including elevated body mass index, waist circumference, and blood pressure. There were 3,803 SSNHL events in the MASLD group during nine years of follow-up, with an incidence rate of 2.44 per 1,000 person-years. MASLD was associated with a significantly increased risk for SSNHL after inverse probability of treatment weighting (adjusted hazard ratio, 1.05; subdistribution hazard ratio, 1.06).

“This finding serves as an important indicator that reflects the impact of MASLD on disease progression from a prognostic perspective, rather than merely examining the occurrence of the disease itself,” the authors write.

Article originally appeared on Medical Xpress

Published in January, the update revises guidance featured in the agency’s June 1998 criteria document for a recommended standard covering occupational noise exposure.

At that time, NIOSH said workers “ideally” should receive individual fit testing for hearing protection but noted that commercially available fit-test systems weren’t readily available. So, “NIOSH instead recommended derating the manufacturer’s labeled noise reduction rating to estimate a worker’s ‘as worn’ hearing protector attenuation,” the update states.

Now, however, modern “advances in research and technology have made it possible to quickly check the attenuation that each worker receives from their preferred hearing protection devices at the worksite,” NIOSH says. Additionally, “several hearing protector fit-test systems are now available” that determine a personal attenuation rating, or PAR, “that accurately reflects the level of sound reduction an individual worker receives while wearing a specific hearing protector.” The PAR also may determine “an individual has achieved a specified level of protection.”

The agency emphasizes that although it recommends the use of individual hearing protector fit testing in the field as a best practice for employers, it doesn’t favor any particular fit-testing method.

Article originally appeared on NIOSH

Navigating this lively jumble of words—and focusing on the ones that matter—is particularly difficult for people with some form of hearing loss. Bustling conversations can become a fused mess of chatter, even if someone has hearing aids, which often struggle to filter out background noise. It’s known as the “cocktail party problem”—and Boston University researchers believe they might have a solution.

A new brain-inspired algorithm developed at BU could help hearing aids tune out interference and isolate single talkers in a crowd of voices. In testing, researchers found it could improve word recognition accuracy by 40 percentage points relative to current hearing aid algorithms.

“We were extremely surprised and excited by the magnitude of the improvement in performance—it’s pretty rare to find such big improvements,” says Kamal Sen, the algorithm’s developer and a BU College of Engineering associate professor of biomedical engineering.

The findings are published in Communications Engineering.

Some estimates put the number of Americans with hearing loss at close to 50 million; by 2050, around 2.5 billion people globally are expected to have some form of hearing loss, according to the World Health Organization.

“The primary complaint of people with hearing loss is that they have trouble communicating in noisy environments,” says Virginia Best, a BU Sargent College of Health & Rehabilitation Sciences research associate professor of speech, language, and hearing sciences. “These environments are very common in daily life and they tend to be really important to people—think about dinner table conversations, social gatherings, workplace meetings. So, solutions that can enhance communication in noisy places have the potential for a huge impact.”

As part of the research, they also tested the ability of current hearing aid algorithms to cope with the cacophony of cocktail parties. Many hearing aids already include noise-reduction algorithms and directional microphones (beamformers) designed to emphasize sounds coming from the front.

“We decided to benchmark against the industry standard algorithm that’s currently in hearing aids,” says Sen. That existing algorithm “doesn’t improve performance at all; if anything, it makes it slightly worse. Now we have data showing what’s been known anecdotally from people with hearing aids.”

Sen has patented the new algorithm—known as BOSSA, which stands for biologically oriented sound segregation algorithm—and is hoping to connect with companies interested in licensing the technology. He says that with Apple jumping into the hearing aid market—its latest AirPod Pro 2 headphones are advertised as having a clinical-grade hearing aid function—the BU team’s breakthrough is timely: “If hearing aid companies don’t start innovating fast, they’re going to get wiped out, because Apple and other startups are entering the market.”

Successfully segregating sounds

For the past 20 years, Sen has been studying how the brain encodes and decodes sounds, looking for the circuits involved in managing the cocktail party effect. With researchers in his Natural Sounds & Neural Coding Laboratory, he’s plotted how sound waves are processed at different stages of the auditory pathway, tracking their journey from the ear to translation by the brain. One key mechanism: inhibitory neurons, brain cells that help suppress certain, unwanted sounds.

“You can think of it as a form of internal noise cancelation,” he says. “If there’s a sound at a particular location, these inhibitory neurons get activated.”

According to Sen, different neurons are tuned to different locations and frequencies.

The brain’s approach is the inspiration for the new algorithm, which uses spatial cues like the volume and timing of a sound to tune into or tune out of it, sharpening or muffling a speaker’s words as needed.

“It’s basically a computational model that mimics what the brain does,” says Sen, who’s affiliated with BU’s centers for neurophotonics and for systems neuroscience, “and actually segregates sound sources based on sound input.”

A physicist who later trained in neuroscience, Sen says he came to BU in part because of the opportunity to work with the University’s Hearing Research Center, where he’s now a faculty member. He turned to clinical researchers for help testing the algorithm.

“Ultimately, the only way to know if a benefit will translate to the listener is via behavioral studies,” says Best, an expert on spatial perception and hearing loss, “and that requires scientists and clinicians who understand the target population.”

Formerly a research scientist at Australia’s National Acoustic Laboratories, Best helped design a study using a group of young adults with sensorineural hearing loss, typically caused by genetic factors or childhood diseases. In a lab, participants wore headphones that simulated people talking from different nearby locations. Their ability to pick out select speakers was tested with the aid of the new algorithm, the current standard algorithm, and no algorithm. Boyd helped collect much of the data and was the lead author on the paper.

Applying the science beyond hearing loss: ADHD and autism

Reporting their findings, the researchers wrote that the “biologically inspired algorithm led to robust intelligibility gains under conditions in which a standard beamforming approach failed. The results provide compelling support for the potential benefits of biologically inspired algorithms for assisting individuals with hearing loss in ‘cocktail party’ situations.”

They’re now in the early stages of testing an upgraded version that incorporates eye-tracking technology to allow users to better direct their listening attention.

The science powering the algorithm might have implications beyond hearing loss too.

“The [neural] circuits we are studying are much more general purpose and much more fundamental,” says Sen. “It ultimately has to do with attention, where you want to focus—that’s what the circuit was really built for. In the long term, we’re hoping to take this to other populations, like people with ADHD or autism, who also really struggle when there are multiple things happening.”

Article originally appeared on Medical Xpress 

It is largely caused by mutations in genes, but many of these genes remain to be discovered. Understanding the exact mutations that cause deafness could hold the key to devising treatments.

Professor Andrea Streit, expert in developmental neurobiology at King’s College London, said: “Human genetics approaches have identified hundreds of ‘deafness loci’ – regions on chromosomes associated with deafness.

These regions contain many genes, and the challenge is to identify the gene that causes deafness when mutated.”

The study, led by King’s College London in collaboration with George Washington University, US, discovered new candidates for these so called ‘deafness genes’.

With previous research identifying mutations in a protein, Six1, causing hearing loss, the team focused their investigation on the genes regulated by this protein.

The researchers used computer-based methods to predict more than 150 potential Six1 targets in ear progenitor cells (cells which eventually form the entire inner ear) from chick embryos.

Selecting four of those targets for further investigation, they revealed that Six1 binds to the DNA regions that regulate their expression and that reducing levels of Six1 stopped these genes from being activated.

The team then showed that the vast majority of the genes found in chick are also expressed in human ear progenitors, and that a quarter of them fall into the chromosome regions associated with deafness.

Professor Andrea Streit said: “It was very exciting to find that some of the genes regulated by Six1 are located in regions deafness loci. This makes them priority candidates for being causative genes of congenital hearing loss.”

The scientists also discovered that some of the DNA regions that control Six1 target gene expression are conserved in birds and humans.

This finding suggests that despite 600 million years of evolution, Six1 and its molecular mechanisms are similar in both birds and humans. They may therefore control fundamental biological processes in ear development.

Professor Andrea Streit, added: “It is unusual that regulatory sections of DNA, like the ones we studied, are highly conserved across species. The fact that we find them to be very similar from birds to humans indicates their critical role.”

The team believe further research into Six1 and the genes it regulates could provide insight into the molecular mechanisms that control how the ear normally develops.

Article originally appeared on Neuroscience News

The World Health Organization (WHO) and the International Telecommunication Union (ITU) are highlighting the first global standard for safe listening in video gameplay and esport activities, which aims to reduce the risk of and prevent hearing loss among gamers. Previously, no safe listening guidelines or standards existed for video gameplay devices or software.

• Sound allowance tracking to measure the player’s sound exposure.
• Safe listening messages that provide players with information on sound usage, including predictions on when their sound limit will be reached.
• A user-friendly volume control system that can be easily adjusted.
• A “headphone safety mode” that automatically adjusts the volume when a player changes between headphones and loudspeakers.

• Safe listening warnings and messages for players about the risk of hearing loss from loud sounds and prolonged exposure during gameplay activities.
• Independent volume controls for different sound categories, allowing players to adjust levels and mute various sounds within the game.
• Adapting the soundtrack, genre and sound design of each game with safe listening features
• A “headphone safety mode” within the software that is capable of detecting a switch of audio output between headphones and speakers and automatically reduces the volume.

Hearing loss is increasingly common, particularly as people age, while the prevalence of heart failure is also on the rise, affecting around 64 million people worldwide, note the researchers.

While impaired hearing is associated with an increased risk of cardiovascular disease, principally, it is thought, as a result of the resulting social detachment, no study has comprehensively examined the association between objectively measured hearing ability and the risk of developing heart failure.

In a bid to plug this knowledge gap, the researchers mined the data of 164,431 participants from the UK Biobank, 4369 of whom wore hearing aids. None had heart failure to begin with. The average age of participants was 56, and 89,818 (around 55%) were women.

Their hearing ability was objectively measured using the validated Digit Triplets Test and the speech-reception-threshold (SRT). Participants (160,062) who didn’t wear hearing aids were categorised into three groups according to their performance on the DTT: normal (140,839; 88%); insufficient (16,759;10.5%); and poor (2464; 1.5%).

Comprehensive background information on current health, lifestyle, and psychosocial factors was collected via questionnaires.

Social isolation was assessed using a composite definition in the UK Biobank derived from scores (1-3) for the number of people living in the household, frequency of friend or family visits, and leisure or social activities. Those with a score of 2 or 3 were classified as socially isolated.

Psychological distress was assessed using a four-item version of the Patient Health Questionnaire (PHQ-4), with a score ranging from 0 to 12. Neuroticism, a depression-related personality trait, was assessed using 12 questions from the Eysenck Personality Questionnaire-Revised Short Form.

The development of heart failure among those who were not genetically predisposed to the condition was identified through medical records and death certificates during an average follow up of 11½ years.

During this period, 4449 (nearly 3%) of the participants developed heart failure. SRT levels were significantly positively associated with the risk of developing the condition in participants who didn’t wear hearing aids.

Compared with those with normal hearing, the adjusted heightened risks of developing heart failure were 15% and 28%, respectively, for insufficient and poor hearing, and 26% for hearing aid use.

The associations between SRT levels and heart failure risk were stronger in those without coronary heart disease or stroke at the start of the study.

SRT levels were significantly positively associated with social isolation, psychological distress, and neuroticism among those who didn’t wear hearing aids. And these factors had a substantial role in the observed associations in participants who didn’t wear hearing aids, accounting for 3%, 17%, and 3%, respectively, of the heightened risk of heart failure development.

When the scores for social isolation, psychological distress, and neuroticism were combined among those who had full data on these factors, the total mediating effect was just over 9%.

This was less than the sum of the mediating effects of each individual factor, which amounted to 19.5%, suggesting overlap and interaction between these three factors, say the researchers.

This is an observational study, and as such, can’t establish cause and effect. And data on hearing were collected only at the start of the study, while the participants in the current study were mainly of European descent and healthier than the UK general population, they acknowledge.

But there are plausible biological explanations for their findings, they say. “The rich distribution of capillaries in the…cochlea and the high metabolic demand of the inner ear may render these regions more sensitive to systemic vascular disorders rather than just local circulatory issues,” they suggest.

“Therefore, hearing impairment may reflect vascular health and serve as an early and sensitive predictor of cardiovascular disease, including [heart failure],” they add.

“Of note, both the participants who used hearing aids and those with poor hearing had a similarly significant increase in the risk of incident [heart failure], suggesting that while hearing aids can improve auditory function, they may not address the underlying vascular issues that contribute to the risk of [heart failure],” they continue.

And they explain: “Because hearing problems can lead to difficulties in speech comprehension and poor engagement in social activities, people with hearing impairment are more likely to experience social isolation, psychological distress, anxiety and depression than people without hearing impairment.

“These psychological factors may increase the activity of the sympathetic nervous system and the hypothalamic-pituitary adrenal axis, and enhance inflammation and oxidative stress, thereby accelerating atherosclerosis, increasing peripheral stress, and promoting the development of cardiac remodeling.”

The findings highlight the importance of integrating hearing health assessments into broader cardiovascular risk evaluation frameworks, they conclude. And strengthening psychological intervention in people with hearing impairment may be key to curbing the risk of heart failure, they suggest.

Article originally appeared on News Medical Life Sciences

Emily Ishak, from the Columbia University Irving Medical Center in New York City, and colleagues conducted a prospective cohort study as part of the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS) with up to eight years of follow-up to calculate the population attributable fraction of incident dementia associated with hearing loss in older adults. The analysis included community-dwelling adults aged 66 to 90 years without dementia at baseline who underwent a hearing assessment at ARIC-NCS visit 6 (2016 to 2017).

Of 2,946 participants, 66.1 percent had audiometric hearing loss and 37.2 percent had self-reported hearing loss. The researchers found that the population attributable fraction of dementia was 32.0 percent from any audiometric hearing loss. Similar population attributable fractions were seen by hearing loss severity (16.2 and 16.6 percent for mild hearing loss and moderate or greater hearing loss, respectively). There was no association for self-reported hearing loss with an increased risk for dementia. Those who were 75 years or older, female, and White (30.5, 30.8, and 27.8 percent, respectively) had larger population attributable fractions from audiometric hearing loss relative to those who were younger than 75 years, male, and Black.

“Interventions for sensory health in late life might be associated with a broad benefit for cognitive health,” the authors write. “Future studies should prioritize objective measures of hearing over subjective measures to quantify its preventative potential on dementia risk.”

Article originally appeared on Health Day