Tag Archive: UK Noise Association

New explanation for why older people can’t hear in noisy environments

Photo credit: Filipe Fortes licensed under CC BY-SA 2.0

By Daniel Fink, MD, Chair, The Quiet Coalition

There are already several explanations about why middle-aged and older people can’t understand speech in noisy environments. One may just be high-frequency hearing loss caused by noise, which makes it hard to hear the higher-pitched consonant sounds (F, S, SH, T, V) that allow us to differentiate similar sounding words (Fear, Sear, Shear, Tear, Veer). (See the graph in this CDC Vital Signs Issue.) Another reason may be a phenomenon called “hidden hearing loss,” which is caused by noise damage to nerve junctions (synapses) in the inner ear.

And now a new report indicates that there may also be a brain or central processing problem. A study conducted at the Max Planck Institute in Germany, “analyzed what happens in the brain when older adults have trouble listening in loud environments.”  The researchers “monitored the brains of 20 younger adults ages 18 to 31, and 20 older adults in their 60s and 70s, during a listening task” in which constant background noise was played while participants were told to focus on certain targeted sounds.

What the researchers found was that “the younger adults were able to zero in on the target signals while filtering out the irrelevant noise,” but the older participants had “a harder time tuning out the background noise.” What remained unclear was whether the “degradation of the ear’s ability to hear actually leads to a decline in the brain’s ability to filter out noise and hear a single sound,” or whether “the brain’s listening ability erodes independently of any changes going on in the ear.”

As for why older people have a difficult time understanding speech in noisy environments, it most likely is that all three factors occur to varying degrees in various individuals. But one thing is certain, preventing hearing loss is simple: avoid loud noise. And improving the ability of people young and old to follow conversations is also simple: turn down the volume in indoor places.

Link via the UK Noise Association.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He serves on the board of the American Tinnitus Association, is the interim chair of Quiet Communities’s Health Advisory Council, and is the founding chair of The Quiet Coalition, an organization of science, health, and legal professionals concerned about the impacts of noise on health, environment, learning, productivity, and quality of life in America.

 

Feeling a bit stressed? Maybe this will help.

It’s true: The sound of nature helps us relax.  Researchers at the Brighton and Sussex Medical School (BSMS) have “found that playing ‘natural sounds’ affected the bodily systems that control the flight-or-fright and rest-digest autonomic nervous systems, with associated effects in the resting activity of the brain.” Science Daily reports that “[w]hile naturalistic sounds and ‘green’ environments have frequently been linked with promoting relaxation and wellbeing, until now there has been no scientific consensus as to how these effects come about.”

The researchers “conducted an experiment where participants listened to sounds recorded from natural and artificial environments,” during which their brain activity was measured and autonomic nervous system activity was monitored. The research team found that activity in the “default mode network of the brain (a collection of areas which are active when we are resting) was different depending on the sounds playing in the background.” Long and short, when listening to natural sounds “the brain connectivity reflected an outward-directed focus of attention,” whereas artificial sounds caused the brain connectivity to reflect “an inward-directed focus of attention, similar to states observed in anxiety, post-traumatic stress disorder and depression.”  Interestingly, the change in brain activity depended on the participant’s stress level–those showing the greatest stress before the experiment “showed the greatest bodily relaxation when listening to natural sounds,” but those who were already relaxed showed “a slight increase in stress” when “listening to natural compared with artificial sounds.”

While helpful for treating people with anxiety, the study results will have a much greater reach. Science Daily notes that “the study of environmental exposure effects is of growing interest in physical and mental health settings, and greatly influences issues of public health and town planning.” Could a restful natural spot will be coming to your town?

Link via UK Noise Association.