Battling Noise with Nutrients, Listening in Background Noise Among Topics to be Covered at International Conference of Ear, Nose, Throat Researchers
|| Scientists supported by the National
Institute on Deafness and Other Communication Disorders (NIDCD),
one of the National Institutes of Health, will be presenting
their latest research findings at the 2009 Midwinter Meeting
of the Association for Research in Otolaryngology (ARO) in
||February 14-19, 2009
||The Baltimore Marriott Waterfront,
Additional Information: Research topics to be
presented by NIDCD-funded scientists will include:
Our Aging Ears and Brains: Why Listening in Background
Noise Gets Tougher as We Age
Older adults often have trouble understanding what someone
is saying when surrounded by background noise, such as at a restaurant
or party, but their ears may not be the only problem. Researchers
at the Medical University of South Carolina are studying how much
the brain plays a role as well. Using magnetic resonance imaging
(MRI), the researchers performed brain scans on 36 older and younger
adults as they tested their ability to identify certain words,
some of which had been filtered to make them difficult to understand.
The researchers analyzed the scans to functionally define speech-
and attention-related areas of the brain and then examined the
volume of gray matter in those regions for age-related changes.
They found that, in general, older adults were significantly worse
at identifying words than younger adults in challenging listening
conditions. Even after eliminating variation due to possible hearing
loss, these differences in performance corresponded closely to
a loss of volume in a small portion of the auditory cortex, a
part of the brain that processes what our ears hear. What’s more,
the relationship between the volume of gray matter in this brain
region and the ability to identify words was present in both younger
and older adults, suggesting that aging may intensify developmental
problems that a person may have in understanding speech. The findings
could help us better understand presbycusis, a type of hearing
loss brought on by aging that also involves the brain’s ability
to process what the ears hear.
The poster “Structural Integrity of Speech-Related Temporal Lobe
Cortex Predicts Age-Related Differences in Word Recognition” (#141)
takes place Sunday, February 15, at 1:00 p.m. in the Grand Ballroom.
Can a Dietary Supplement Stave Off Hearing Loss?
Many people take a vitamin each morning to maintain good nutrition,
energy, bone strength, and overall health. Can popping a pill
also protect our hearing against damage caused by loud noise?
Researchers at the University of Michigan and the University of
Florida, together with the biosciences company OtoMedicine, have
demonstrated that temporary noise-induced hearing loss — the
hearing loss you might feel immediately after attending a loud
concert but that goes away in a day or two — can be prevented
in guinea pigs by a combination of the antioxidants beta-carotene,
vitamin C, and vitamin E and the mineral magnesium, when administered
before exposure to a loud sound. Because repeated bouts of temporary
noise-induced hearing loss may lead to permanent noise-induced
hearing loss, the scientists hope to determine whether prevention
of the former can stave off the latter in various animal models
and in humans.
In a second study conducted with colleagues at Washington University,
the researchers demonstrated that permanent noise-induced hearing
loss can also be prevented in mice through the combination of
the same nutrients administered before exposure to a loud noise.
(They showed similar results in guinea pigs in an earlier study.)
However, unlike in guinea pigs, they found that the nutrients
protect a structure in the mouse’s inner ear that is implicated
in age-related hearing loss. They plan to test whether the nutrient
supplements may be able to prevent this type of hearing loss as
well. The researchers are currently conducting clinical trials
of the supplements’ ability to prevent noise-induced hearing loss
in college students, military personnel, and factory workers in
Florida, Sweden, and Spain.
The posters "Reduction in Permanent Noise-Induced Threshold Deficits
in Mice Fed a Combination of Dietary Agents" (#826) and "Prevention
of Temporary Noise-Induced Threshold Deficits Using Dietary Agents" (#827)
take place Wednesday, February 18, at 1:00 p.m. in the Grand Ballroom.
Finding the Words: What Our Brains Tell Us about Language Disorders
The presentation "Brain Networks for Language Production
and Comprehension" (#227)
takes place Sunday, February 15, at 7:05 p.m. in the Harborside
Ballroom A-C. The presentation "A Case Study of Expressive
Aphasia in an Opera Singer" (#228)
immediately follows at 7:35 p.m. in the same location.
We rely mightily on our brains to produce and understand language — whether
simply naming a person or object or engaging in a lively discussion.
Technologies in brain imaging — from those involving the brain’s
electrical activity to those measuring blood flow to regions of
the brain — can tell us a lot about what’s
happening in the process. Dr. Allen Braun, chief of the language
section in NIDCD’s
Division of Intramural Research, will demonstrate how a combination
of imaging technologies can be used to teach us more about how
the brain produces and comprehends language, both in people with
normal skills and those with a language disorder. In addition,
he’ll show how language used in its most natural form – to communicate – is
most effective in bringing to light the true symptoms of a language
disorder. In the same workshop, an opera singer who suffered a
severe stroke in 1995 will describe her experience with expressive
aphasia, a condition that makes it difficult to express language.
She will also perform several music selections.
Maintaining Balance and Listening at Same Time May Become More
Difficult for Older Adults
Listening to a conversation or audio book while walking or exercising
sounds simple enough for most people, but it may become more difficult
for people in their upper 70s and above, according to new research
from the University of Pittsburgh Medical Center. Researchers
evaluated how well three groups of adults — healthy young (ages
24-27), old (ages 65-71), and “old-old” (ages 76-82 years) —
were able to conduct a listening exercise while their visual and
balance systems were kept busy. Seated in swivel chairs that were
either upright or at a 30-degree tilt, the volunteers performed
two listening-related tasks while motionless or spinning in darkness
or in light. In one task, they listened to a high- or low-pitch
tone and pressed a button in their right or left hand depending
on the pitch. In the second task, volunteers listened to tones
in their right or left ears and pressed the corresponding button.
The researchers found that, in general, all age groups reacted
more slowly to the audio cues when spinning than when motionless.
However, this was especially true for people in the oldest age
group. They also found that stimulation of the ear’s gravity-sensing
organs — through the 30-degree tilt of the chair — was especially powerful in
slowing down a person’s auditory reaction time. Again, this effect
was most pronounced for people in the oldest age group. The National
Institute on Aging also supported this research.
The poster "Visual-Vestibular Stimulation Interferes with Auditory
Information Processing Task Performance in Older Persons" (#961)
takes place Wednesday, February 18, at 1:00 p.m. in the Grand
Built-in Volume Control Helps Protect Auditory Nerve Against Loud
When we hear a sound, sensory cells in our inner ear trigger the
release of a chemical — called a neurotransmitter — to neighboring
nerve cells, which, in turn, relay the auditory message to our
brain. When our ears are exposed to very loud sounds, such as
the blast of a firecracker, too much of the neurotransmitter is
released, damaging these auditory nerve cells and causing hearing
loss. NIDCD-funded researchers at the Massachusetts Eye and Ear
Infirmary, Harvard Medical School, have found that auditory nerve
cells temporarily reduce the expression of a key neurotransmitter
receptor on their surfaces when exposed to loud noise, and they
wanted to know why. In a new study on mice, the researchers used
a drug to block the ability of the auditory nerve cells to remove
the receptor and then exposed the mice to a moderately loud sound
that, under normal conditions, would not damage the nerve cells.
They found that the mice given the blocking drug experienced hearing
loss for at least six hours following exposure to the normally
harmless sound. Also, the blocker accelerated the death of auditory
nerve cells that had been incubated in the lab with neurotransmitter
chemicals that are normally released during sound stimulation.
The researchers suggest that the auditory nerve regulates the
expression of these surface receptors as a way to protect itself
against the chemical overload caused by loud noise. Although the
scientists believe that auditory nerve cells can rid their surfaces
of the receptor by as much as 50 percent, this may not be enough
protection against all loud sounds.
The poster "Regulated Expression of Surface AMPA Receptors Reduces
Excitotoxicity in Auditory Neurons" (#80) takes place Sunday,
February 15, at 1:00 p.m. in the Grand Ballroom.
How Your Brain Deciphers Cocktail Party Banter
Anyone who has tried to carry on a conversation in a roomful of
talkers knows how difficult it can be to concentrate on what one
person is saying while tuning everyone else out. Researchers at
the University of Maryland, Johns Hopkins University, and Starkey
Laboratories, Inc. have a better picture of how the brain manages
this feat. Using magnetoencephalography (MEG), an imaging technique
that measures magnetic fields produced by changes in the brain’s
electrical activity, the researchers played two competing audio
streams into the ears of 26 healthy volunteers and asked them
to listen to one stream while ignoring the other. One group concentrated
on a faster-paced series of beeps while the second group focused
on a slower beep pattern; the groups later switched tasks to focus
on the other audio stream. The researchers also introduced an
occasional change in the rhythm to find out if the study volunteers
noticed. Among their results, researchers found that people listening
to one stream did not detect pattern changes in the other stream.
In addition, although the brain showed neural activity representing
both audio streams, the amount of neural activity was much stronger
and more in sync for the stream on which a person was concentrating.
The poster "Competing Streams at the Cocktail Party - A Neural
and Behavioral Study of Auditory Attention" (#879) takes place
Wednesday, February 18, at 1:00 p.m. in the Grand Ballroom.
For Implant-Wearing Guitarist, Hearing the Notes Not Necessary
for Staying on Key
The cochlear implant is a remarkable technology that helps people
with severe hearing loss to understand speech, even when on the
telephone. Listening to music, however — even a simple melody
— remains difficult for many implant wearers. Researchers at
the University of California, Irvine, and Peking University, Beijing,
have found one cochlear-implant-wearing musician who is able to
tune his guitar without help from an electronic tuner. Instead
of listening to the tones of the strings, the guitarist counts
the beats between mismatched notes. This is based on the principle
that when two notes are out of tune with one another, an audible
pulsing or beating occurs. The greater the mismatch, the faster
the beats. Musicians with normal hearing frequently listen to
the pulsing in addition to the tones to make sure their instruments
are properly tuned. After plugging the guitarist’s
speech processor into a computer, the researchers found that the
output of the processor clearly reflected this same beating, which
implant users are known to reliably detect. The researchers suggest
that this is another application, previously unknown, for cochlear
The poster "Accurate Tuning of a Guitar by a Cochlear Implant
takes place Monday, February 16, at 1:00 p.m. in the Grand Ballroom.
For more information about the Association for Research in Otolaryngology,
visit their Web site at www.aro.org.
NIDCD supports and conducts research and research training on
the normal and disordered processes of hearing, balance, smell,
taste, voice, speech and language and provides health information,
based upon scientific discovery, to the public. For more information
about NIDCD programs, see the Web site at www.nidcd.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.