Hearing tests can fail to diagnose hearing loss: study

April 21, 2017

Washington, Apr 21: A team of US researchers has revealed that the traditional clinical hearing tests often fail to diagnose patients with a common form of inner ear damage, which otherwise might be detected by some behavioural tests.

HearingAccording to researchers, the reason why some forms of hearing loss may go un-recognised in the clinic is that hearing involves a complex partnership between the ear and the brain and the central auditory system can compensate for significant damage to the inner ear by turning up its volume control, partially overcoming the deficiency.

This type of "hidden hearing loss" paradoxically presents itself as essentially normal hearing in the clinic, where audiograms -- the gold-standard for measuring hearing thresholds -- are typically conducted in a quiet room.

"You can have tremendous damage to inner hair cells in the ear that transmit information to the brain and still have a normal audiogram," said lead study author Richard Salvi from University at Buffalo.

"But people with this type of damage have difficulty in hearing in certain situations, like hearing speech in a noisy room. Their thresholds appears normal," Salvi added. About 95 percent of sound input to the brain comes from the ear's inner hair cells.

"Ear damage reduces the signal that goes the brain and it results trouble in hearing, but that's not what's happening here, because the brain "has a central gain control, like a radio, the listener can turn up the volume control to better hear a distant station." Salvi stated.

The sound is converted to neural activity by the inner hair cells in the auditory part of the ear, called the cochlea.

Sound-evoked neural activity then travels from the cochlea to the auditory nerve and into the central auditory pathway of the brain. For people with inner hair cell loss, sound is less faithfully converted to neural activity in the cochlea.

It is not clear how many people might have this type of hearing loss, but Salvi noted in the journal Frontiers in Neuroscience that it is a common complaint to have difficulty hearing in noisy environments as people get older.

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Agencies
May 20,2020

Washington D.C., May 20: While a dairy-rich diet is helpful in meeting the body's calcium requirement, outcomes of a large international study links eating at least two daily servings of dairy with lower risks of diabetes and high blood pressure.

The dairy-rich diet also proved to lower the cluster of factors that heighten cardiovascular disease risk (metabolic syndrome). The study was published online in journal BMJ Open Diabetes Research & Care.

The observed associations were strongest for full-fat dairy products, the findings indicated.

Previously published research has suggested that higher dairy intake is associated with a lower risk of diabetes, high blood pressure, and metabolic syndrome. But these studies have tended to focus on North America and Europe to the exclusion of other regions of the world.

To see whether these associations might also be found in a broader range of countries, the researchers drew on people taking part in the Prospective Urban Rural Epidemiology (PURE) study.

Participants were all aged between 35 and 70 and came from 21 countries: Argentina; Bangladesh; Brazil; Canada; Chile; China; Colombia; India; Iran; Malaysia; Palestine; Pakistan; Philippines, Poland; South Africa; Saudi Arabia; Sweden; Tanzania; Turkey; United Arab Emirates; and Zimbabwe.

Usual dietary intake over the previous 12 months was assessed by means of Food Frequency Questionnaires. Dairy products included milk, yogurt, yogurt drinks, cheese and dishes prepared with dairy products, and were classified as full or low fat (1-2 percent).

Butter and cream were assessed separately as these are not commonly eaten in some of the countries studied.

Information on personal medical history, use of prescription medicines, educational attainment, smoking and measurements of weight, height, waist circumference, blood pressure and fasting blood glucose were also collected.

Data on all five components of the metabolic syndrome were available for nearly 113,000 people: blood pressure above 130/85 mm Hg; waist circumference above 80 cm; low levels of (beneficial) high-density cholesterol (less than 1-1.3 mmol/l); blood fats (triglycerides) of more than 1.7 mmol/dl; and fasting blood glucose of 5.5 mmol/l or more.

Average daily total dairy consumption was 179 g, with full-fat accounting for around double the amount of low fat: 124.5+ vs 65 g.

Some 46, 667 people had metabolic syndrome--defined as having at least 3 of the 5 components.

Total dairy and full-fat dairy, but not low-fat dairy, was associated with a lower prevalence of most components of metabolic syndrome, with the size of the association greatest in those countries with normally low dairy intakes.

At least 2 servings a day of total dairy were associated with a 24 percent lower risk of metabolic syndrome, rising to 28 percent for full-fat dairy alone, compared with no daily dairy intake.

The health of nearly 190,000 participants was tracked for an average of nine years, during which time 13,640 people developed high blood pressure and 5351 developed diabetes.

At least 2 servings a day of total dairy was associated with a 11-12 percent lower risk of both conditions, rising to a 13-14 percent lower risk for 3 daily servings. The associations were stronger for full fat than they were for low-fat dairy.

This is an observational study, and as such can't establish the cause. Food frequency questionnaires are also subject to recall, and changes in metabolic syndrome weren't measured over time, all of which may have influenced the findings.

Nevertheless, the researchers suggest: "If our findings are confirmed in sufficiently large and long term trials, then increasing dairy consumption may represent a feasible and low-cost approach to reducing [metabolic syndrome], hypertension, diabetes, and ultimately cardiovascular disease events worldwide."

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Agencies
May 6,2020

Washington D.C., May 5: Working from home has become the new normal ever since the outbreak of coronavirus and in today's time the work duties can be easily dealt with by means of mobile devices at home.

However, this easy use of technology, mobile devices for that matter, has the potential to blur the fine line between work and the other daily life routines.

But, contrary to the belief, a study at the University of Jyvaskyla reveals that the mixing of work and other daily life routines may have more benefits than previously assumed, and points to the importance of boundary-spanning communication.

A smartphone enables phone calls, email, and file transfers from the comfort of home. The study shows that there may be more effective ways to maximise the benefits of smartphone use, without diminishing employees' flexibility and the use of these technologies.

"People often forget to talk about positive effects, such as autonomy and freedom the employees gain when they have the flexibility to schedule their work," said Postdoctoral Researcher Ward van Zoonen from JYU, who with his colleagues examined the use of smartphones for work matters outside working hours.

The study paid special attention to the benefits of talking about domestic matters with the immediate supervisor outside the working hours given to an employee.

"This reduces the conflict between work and other life," van Zoonen said.

"If people in an organisation strive for more dialogue between employees' different life domains, it is possible to create a functional environment where people can talk about different matters."

The research findings show that when employees communicate across boundaries and talk at work about their life in other respects, they can receive new kinds of support and understanding from their immediate supervisor.

"This kind of communication creates a low threshold for contacting one's supervisor, which helps employees build a balance between the different domains of their lives and strengthens their organisational identification," said Professor Anu Sivunen describing the findings.

This means that tight working time restrictions to protect employees might not be beneficial after all, if they hinder reaching the positive results indicated in this research.

For the study, a survey was taken of 367 employees who were asked questions such as -- how much they talk about their work with their family, and how much they talk about their family with their immediate supervisor.

"Both supervisors and their employees answered the surveys, and the study actually focused on their mutual communication," Sivunen said.

"Usually people at workplaces are interested in how communication within the work community is succeeding. It is often forgotten how an immediate supervisor can take an employer's other life into account and thereby help the employee gain work-related benefits."

"Communication with one's immediate supervisor during flexible working hours, also on matters other than work, could ease the daily lives of many employees if they could share the possible challenges of their family life or free time with their supervisor in these settings," Sivunen added.

According to the study, such a practice could make the supervisor aware of the employee's situation as he/she works from home and the related impacts on their work performances.

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