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World
Audiology News - archive of stories for
2006
These stories were previously featured in the first page
of the News Section in this website.
Please note: with passage of time some
of these stories may no
longer be available to view on their original websites of publication.
Folic Acid May Slow Age-Related Hearing Loss
A study by Jane Durga and colleagues (Cognitive Sciences Group, Nutrition & Health
Department, Nestle Research Center - Lausanne, Switzerland) has found
that age-related hearing loss, a common problem among the elderly, might
be related to inadequate levels of folic acid (folic acid is a B vitamin
also known as folate). The researchers found that people who took a folic
acid supplement had less decline in hearing low-frequency sounds over
time, compared with people who didn't take the supplement. The researchers
randomly assigned 728 older Dutch men and women between the ages of 50
and 70 to receive either 800 micrograms of a folic acid supplement or
a placebo daily for three years. In Addition any subjects who had low
homocysteine levels at the start of the study were excluded because there
is evidence that folate may improve hearing by lowering plasma homocysteine
levels. The study was conducted in the Netherlands because, unlike in
some other countries the Netherlands does not fortify its food with folic
acid (in the USA and some other countries folic acid is added to food
in order to protect against birth defects). After three years, those
who received folic acid pills had less low-frequency hearing loss than
did placebo recipients. The difference was slight: 0.7 decibels. The
smallest change in sound intensity most people can notice is 1.0 decibels.
Researchers said no slowing of high-frequency hearing loss was noted,
possibly because high-frequency hearing loss begins earlier than age
50. The researchers wrote that the effect required confirmation, especially
in populations from countries with folic acid fortification programs.
This work is published in the 2nd January 2007 issue of the Annals of
Internal Medicine. - Reuters
Health,
European Research, 1st January 2007 (see also Health
Day News  , 3rd January
2007)
December
2006
Why Cochlear Implant Users Have Difficulty Understanding Tonal Languages
It’s been shown that the left side of the brain processes language and
the right side processes music; but is this the same for a language like Mandarin
Chinese, which is musical in nature with wide tonal ranges? Researchers (University
of California, Irvine, USA) and colleagues from China (University of Science
and Technology of China, Hefei) have studied brain scans of subjects as they
listened to spoken Mandarin. They found that the brain processes the music, or
pitch, of the words first in the right hemisphere before the left side of the
brain processes the semantics, or meaning, of the information. This shows that
language processing is more complex than previously thought, and it gives clues
to why people who use auditory prosthetic devices have difficulty understanding
Mandarin. Researcher Fan-Gang Zeng said that in the English language, changes
in pitch dictate the difference between a spoken statement and question, or in
mood, but the meaning of the words does not change. This is different in Mandarin,
where changes in pitch affect the meaning of words. Most cochlear implant devices
lack the ability to register large tonal ranges, which is why these device users
have difficulty enjoying music, or understanding a tonal language. Fan-Gang Zeng
and colleagues have made advances in cochlear implant development, discovering
that enhancing the detection of frequency modulation (FM) significantly boosts
the performance of many hearing aid devices by increasing tonal recognition,
which is essential to hearing music and understanding certain spoken languages
like Mandarin. This study appears in the Proceedings of the National Academy
of Sciences. - University
of California, Irvine News ,
USA & Chinese Research, 12th December 2006
October
2006
Otoferlin, a Critical Hearing Gene, Helps Send Auditory Messages to Brain
By studying a gene earlier linked to deafness in humans, researchers
(at Institut Pasteur in Paris, France) now have new insight into the
molecular process by
which components of the inner ear send messages to the brain. The current study,
following up a report by Christine Petit's team several years ago, shows that
people with a recessive form of deafness harbour two abnormal copies of the
otoferlin gene. They also had some evidence hinting that the gene might
act as a calcium
sensor with an important role in neurotransmitter release by the inner hair
cells. Loss of inner hair cell function through any defects results
in total deafness,
as messages cannot get through when an inner hair cell is stimulated, where
channels open up allowing calcium to flow in. In turn, that influx
of calcium leads to
small "sacs" full of neurotransmitter to fuse with the cell membrane,
releasing their contents into the space, or synapse, between the sensory cells
and auditory nerve endings. That chemical release allows nerve messages to be
passed from one neuron to another. In inner hair cells, those neurotransmitter-filled
vesicles (the sacs) are held in place at the cell membrane by tethers known as "ribbons".
This study further reports that otoferlin activity in the cochlea occurs only
in the inner hair cells, where it concentrates in the ribbon-associated synaptic
vesicles. The otoferlin protein binds calcium and interacts with other proteins
known to play a role in neurotransmitter release. It was also found that mice
lacking the gene otoferlin are profoundly deaf. The profoundly deaf mice suffered
a complete loss of neurotransmitter release from their inner hair cells, despite
having an apparently normal "ribbon synapse" and calcium flow. The
findings led to the conclusion that otoferlin is essential for a late step
of neurotransmitter release and may act as the major calcium sensor - triggering
membrane fusion at the inner hair cell ribbon synapse. The findings also have
therapeutic implications, as they suggest that people who are deaf as a result
of defects in otoferlin may benefit from cochlear implants. Otoferlin-linked
deafness is an auditory neuropathy, a class of hearing impairment for which
the
best course of treatment has remained uncertain, so in these circumstances
cochlear implant may be an option. The team reports its findings in the 20th
October 2006,
issue of the journal Cell, published by Cell Press. - EurekAlert,
French Research, 19th October 2006
Hearing and Vision Loss Go Hand-in-Hand With Aging
Australian researchers have found that hearing and vision loss
often occur together in older adults. The study of over 1,900 adults
of between 50 and 70 years of age found that those with vision loss
were more likely to also have hearing loss, and vice-versa. With further
investigation, the researchers concluded that cataracts and age-related
macular degeneration (the two most common causes of vision loss in
older people) were both independently associated with hearing loss.
The study authors suggested a number of reasons for this link between
vision and hearing loss. Both conditions are regular consequences of
aging and both share common risk factors, including smoking, hardening
of the arteries, and diabetes. Further studies are needed to understand
the relationship between visual and hearing impairments in older persons
and to determine whether intervention to improve these impairments
could delay biological aging. This work was published in the 9th October
2006 issue of the journal Archives of Ophthalmology. - Health
Day News , Australian
Research, 11th October 2006
September
2006
In Memoriam: Denzil Brooks
Dr Denzil N Brooks recently passed away on 7th September 2006.
Denzil had a career in Audiology that spanned over four decades, during
which he helped many people. He was a very charismatic speaker and
his enthusiasm for audiology showed during his various speaking engagements
and in his numerous publications. He will be fondly remembered as "a
scholar and a gentleman" and sadly missed by all. - aud.org.uk,
UK Audiology News, 19th September 2006
August
2006
Remote Control of Human Walking and Balance - by Stimulating Semicircular
Canals
Work carried out by Richard C. Fitzpatrick and Jane E. Butler (University
of New South Wales in Sydney, Australia) and Brian L. Day (University
College London, UK). has shown that stimulation of the semicircular
canals can artificially control human walking and balance. The work
was carried out in order to improve our understanding of how our vestibular
system helps us maintain an upright posture. During this study electrical
currents were applied across the heads of people whilst they walked.
It was found that the electrical stimulus could be applied in a way
that allowed a person who was walking straight ahead to be steered
by "remote control" without their balance being affected.
To investigate how the body's ability to sense head movements can contribute
to balance control and guidance control, the researchers stimulated
nerves that normally communicate signals from the semicircular canals
(structures that are part of the vestibular system that assists in
orientation and balance). It was found that artificial stimulation
of semiciruclar canal nerves afforded "remote control" that
was accurate enough to keep subjects on pathways and avoiding obstacles
while walking blindfolded through botanical gardens. It was also found
that the same stimulus could be used to disturb upright balance, causing
the subject to lean in one direction or the other, but without having
any effect on steering his walking. This new work has important implications
for understanding how the brain processes sensory signals. This work
can be found in the 8th August 2006 issue of the journal Current Biology,
published by Cell Press. - EurekAlert,
Australian & UK Research, 7th August 2006
July
2006
Nicotine Exposure During Pregnancy Leads to Hearing Problems in Children
It is know that children of women who smoke during pregnancy can
develop hearing-related cognitive deficits and for the first time,
researchers believe they have evidence that not only implicates nicotine
as the culprit, but also shows what the substance does to the brain
to cause these deficits. Researchers (University California, Irvine
- USA) have showed that nicotine exposure during the equivalent of
a human’s third trimester in rats led to hearing-related cognitive
problems. This is the first time a study has demonstrated this link.
Further tests then revealed that the probable cause of the deficits
was damage to the receptors in the brain that are sensitive to nicotine,
which seems to occur when humans or animals are exposed to the substance
during development. The lead author of the study (given in the European
Journal of Neuroscience), Raju Metherate, said that the study was significant
because it suggests what aspect of smoking is so harmful in pregnancy
when it comes to cognitive hearing deficits. Nicotine shares a receptor
with the neurotransmitter acetylcholine, which is important for a number
of cognitive functions. It is thought that when people are paying attention
to something, such as an important sound, acetylcholine is released
into the brain. It then interacts with the nicotinic-acetylcholine
receptor and if that receptor is damaged due to prenatal exposure to
nicotine, acetylcholine cannot bind with it and increased sensitivity
to the important sound is lost. Given the importance of acetylcholine
to a number of brain functions, a loss of nicotinic-acetylcholine receptors
may have a negative effect on other higher cognitive functions and
may also impair vision and other senses. However it has been shown
in previous studies that Nicotine seemed to actually enhance cognitive
processing when administered to adults. This was also the case in this
study as it was found that in adult rats the nicotine did appeared
to enhance auditory function, but only if they had not been exposed
to the substance during development.. - University
of California - Irvine News ,
USA Research, 18th July 2006
June
2006
Protocadherin-15 Protein, Tied to Usher Syndrome, May Be Hearing’s
Missing Link
A study carried out by the National Institute on Deafness and Other Communication
Disorders (NIDCD - USA) and the University of Sussex (UK) has shown that a
protein associated with a disorder (Usher Syndrome) that causes deafness and
blindness in people may be a key to unraveling one of the foremost mysteries
of how we hear. It has been found that a protein that is made by the gene that
causes one form of type 1 Usher syndrome, the most common cause of deaf-blindness
in humans, is the most likely player in an important reaction in which sound
is converted into electrical signals that the brain can recognise. It has been
long known that hair cells, small sensory cells in the inner ear, convert sound
energy into electrical signals that travel to the brain, a process called mechanotransduction.
During this process as the stereocilia (projections on the hair cells) are
deflected, pore-like channels on the surface of the stereocilia open up, allowing
potassium to rush in, and generating an electrical signal. The stereocilia
are arranged in tiers, with the tiers being connected together by threadlike
bridges (links). The tip-link that connects the tip of the shorter stereocilium
to the side of the adjacent, taller stereocilium is considered particularly
important for the channel to function, and it is thought that this may be responsible
for opening and closing the channel gate and the knowing make up of the gate
would be important in understanding how the gate mechanism operates. This research
identifies protocadherin-15 to be one of the proteins associated with the tip
link, so answering a question that has been baffling researchers for years.
James F. Battey, director of the NIDCD, stated that as a result of this work
that we are now at the closest point we have ever been to understanding the
mechanism by which the ear converts mechanical energy (or energy of motion)
into a form of energy that the brain can recognize as sound. The findings also
give an insight into how hearing takes place at the molecular level and may
explain why some people temporarily lose their hearing after being exposed
to loud noise due to the link being broken and then re-forming allowing hearing
to be restored. This study is published in the 28th June issue of the Journal
of Neuroscience. - NIH
news (USA), USA & UK
Research, 27th June 2006
May
2006
Cochlear Implantation in Both Ears May Improve Speech Perception in Children
Traditionally candidates for cochlear implantation despite loss of hearing
in both ears have received only one cochlear implant. However in the past
decade there have been numerous studies demonstrating that the majority of
adult patients who receive bilateral cochlear implants are able to realise
significant benefits on measures of speech perception and sound localization.
There have also been initial reports suggesting that bilateral implants may
also be realised by children without language skills. A new study sets out
to determine the extent to which bilateral implantation offers benefits,
focusing on measuring the effects of age at implantation and experience after
activation of the second implant on speech perception performance. The study
suggests that sequential bilateral cochlear implantation, or the placement
of cochlear implants in both of a child’s ears through separate surgeries,
has the potential to improve speech perception abilities in quiet and in
noise. It was found when a second implant was given to a child who was already
a successful user of one cochlear implant (at least 6 months or later after
the first implant) they were able to obtain open set speech discrimination
in their second ear, even when receiving their second implant as late as
13 years of age. The study carried out by Brian R Peters and Jennifer Lake
(both from the Dallas Otolaryngology Cochlear Implant Program, USA), Ruth
Litovsky (University of Wisconsin - Madison, USA) and Aaron Parkinson (Cochlear
Americas) has just been presented at the annual meeting of the American Otological
Society on 20-21 May 2006. - Newswire,
USA Research, 22nd May 2006
Genes on Chromosome 3 May Be Key to Hearing Loss
A new study has suggested that a group of genes on chromosome 3 that are associated
with a type of progressive hereditary hearing loss in younger adults may
also be linked to hearing loss in older men. The study of 50 pairs of elderly
male fraternal twins with hearing loss found evidence of genes linked to
age-related hearing loss on chromosome 3q, near a gene location called DFNA18.
This particular region of DNA is one that was previously tied through other
research to a hereditary form of progressive deafness that begins much earlier
in life. These findings appear in the May issue of the Archives of Otolaryngology
- Head & Neck Surgery and the work was carried out by Holly J. Garringer,
Terry E. Reed (Indiana University, School of Medicine), and colleagues. - Indiana
University, School of Medicine news, USA Research, 15th May
2006
April
2006
Bristol is the Noisiest City in England - peaking at 110dB
An hearing aid company has carried out research into noise levels in cities
in the UK during the rush hour (peak time when people are going to work).
Readings in Bristol peaked at 110dB, closely followed by Leeds at 100dB and
Hull at 97dB. Surprisingly London came in lower than these at 82dB which
was the same as for Liverpool. It is known that prolonged exposure to sounds
above 85 decibels (dB) can cause irreversible damage to hearing .- BBC,
UK News, 27thApril 2006
Aspirin Prevents Antibiotic-Linked Hearing Loss
A new report has found that aspirin can be used to prevent hearing
loss caused by common antibiotics called aminoglycosides, which have
been used to treat acute infections and other conditions over the last
60 years. This work has been published by a U.S.- Chinese team including
Jochen Schacht (University of Michigan Medical School, USA) and others
in the 27th April 2006 issue of the New England Journal of Medicine.
The study included 195 Chinese patients who received 80 milligrams
to 160 milligrams of gentamicin (a type of aminoglycoside) intravenously,
twice daily, for five to seven days. Of those 195 patients, 89 received
aspirin along with the antibiotic and 106 were given a placebo along
with the antibiotic the rate of hearing loss among patients who received
aspirin was 3 percent, compared with 13 percent among the patients
who received the placebo. That translates to a 75 percent lower rate
of hearing loss among patients who received aspirin. This builds on
previous work which showed that this worked well in mice. So the use
of aspirin could be a cheap, easy solution to a longstanding problem.- Health
Day News, USA / Chinese Research, 26th April 2006.
Brain Port to be Used Create Super U.S. Soldiers
We previously brought you a story about the Brain Port device (23rd Nov
2004) and how it had been used to regain normal vestibular function.
The brain port is a device which can help to restore senses, such as
sight and touch be re-routing them to other parts of the body such
as the tongue, skin or ear by allowing one set of sensory information
to substitute for another in the brain. In this new development, in
a quest to create the super warrior of the future, some researchers
(funded by the U.S. Defence Department) are looking at the Brain Port
device in order to give elite soldiers superhuman senses similar to
owls, snakes and fish by routing signals from helmet-mounted cameras,
sonar and other equipment through the tongue to the brain..The research
is being carried out by Dr Anil Raj and others at the Florida Institute
for Human and Machine Cognition (USA). Examples of application could
include giving army rangers 360-degree unobstructed vision at night
and allowing U.S. Navy SEALs to sense sonar in their heads while maintaining
normal vision underwater. One of the test subjects, Michael Zinszer,
a veteran navy diver and director of Florida State University's Underwater
Crime Scene Investigation School, who took part in testing using the
tongue to transmit an electronic compass and an electronic depth sensor
while in a swimming pool, likened the feeling on his tongue to Pop
Rocks candies and said he could feel the outline of an image on his
tongue and that he could easily locate everything. The researches plan
to officially demonstrate the system to navy and U.S. Marine Corps
divers in May. If the military screeners like what they see, it could
be put on a "rapid response" to quickly get in the hands
of military users within the next three to six months. - cnews:
canoe network, USA Research, 24th April 2006
Environmental Toxins Found to Disrupt Hearing in Mammals
Joseph Santos-Sacchi (professor in the Departments of Surgery and
Neurobiology at Yale School of Medicine, USA) and colleagues have new
evidence to show chloride ions are critical to hearing in mammals.
This work builds on previous research showing a chemical used to keep
barnacles off boats might disrupt the balance of these ions in ear
cells. Joseph Santos-Sacchi said that their data was the first to directly
show that chloride ions were crucial for the exquisite sense of hearing.
The work showed that hearing in marine and other mammals could be affected
by environmental toxins, such as tributyl tin (TBT), because they appear
to alter the balance of chloride ions in the outer hair cell." It
was found with guinea pigs that TBT or salicylate (a component of aspirin
and naturally occurring in some plants) could interfere with the ability
to hear.It was also concluded that since many marine animals use echolocation
or sonar to get move around, this could also be contributing to whales
and dolphins beaching and hitting ships. This work is published in
the Journal of Neuroscience (available online from 12 April 2006).
- EurekAlert,
USA Research, 11th April 2006
Veribel, A New Hearing-Aid in the Form of Glasses (Spectacles)
A dutch company has launched a hearing-aid in the form of a pair
of glasses (spectacles) called the Veribel. The new 'hearing-glasses'
have been developed by the Delft University of Technology in the Netherlands.
There are miniature speakers contained in the arms of the glasses frames,
which allows sound to be captured and relayed. These are very different
to many regular hearing aids which intensify sounds from all directions
so noise is heard but not the people they are speaking resulting in
difficulty with understanding what others are saying in spite their
hearing-aids (This can subsequently result in social isolation and
early retirement from jobs). The developers and test users of these
glasses said that the hearing-glasses can provide a solution to this
problem. Each leg of the glasses frame contains four tiny, interconnected
microphones, which selectively intensify the sounds that come from
the front, while dampening the surrounding noise. The result is a directional
sensitivity of +8.2 dB. In comparison, regular hearing aids have a
maximum sensitivity of +4 dB. With this solution, the user can separate
the desired sounds from the undesired background noise. With the glasses
natural sounds to be still heard in the direction in which they are
looking / facing. Both the glasses and the company which is now producing
them as a commercial product are called Varibel. The university said
that the glasses will be available commercially from mid April. - aud.org.uk,
Dutch Research & Development, April 2006 (news source: Delft
University of Technology News release, 6.4.06, - also see: ZDNet,
9.4.06, EETimes,
11.4.06)
Study Examines Loud Music Dependency Disorder
A study conducted at Northeastern University (USA) by Mary Florentine (Professor
of Audiology) and colleagues found that a small group of people simply can’t
stop listening to loud music. This has been named “Loud Music Dependency
Disorder,” or LMDD. Prof. Florentine and other researchers developed
a test to measure LMDD by adapting a model normally used to identify alcohol
dependency. Of the 90 participants, a small group surveyed in a music store
exhibited signs of dependency on loud music much like alcoholics’ “cravings” because
music contributes to rapid and potent mood changes and fulfills a need to
experience. - The
Boston Herald ,
USA Research, 7th April
Sign Language Officially Recognised in New Zealand
On Thursday 6th April 2006, in a landmark decision, New Zealand's parliament
voted to make New Zealand Sign Language the official third language as well
as English and Maori. This means that it can now be used legally in all sorts
of official places such as court rooms. The bill was passed after 20 years
of campaigning by the New Zealand deaf community. This language is unique
as it includes signs to express concepts from both the English and Maori
cultures. There are about 210,000 deaf or hearing impaired people in New
Zealand. - Sydney
Morning Herald (Australia) ,
New Zealand Related News, 7th April 2006 (you may also wish to
see the related
article and video from TVNZ, 6.4.06 - editorial)
March
2006
Dallas Professor Awarded $1.3M to Link Hearing Aids to PDAs
Dr Philip C. Loizou (Erik Jonsson School of Engineering and Computer Science,
University of Texas at Dallas - UTD, USA), has been awarded a three-year,
$1.3-million contract from The National Institutes of Health (NIH) to build
an interface that will enable personal digital assistants (PDAs) to transmit
sounds to an implant worn in the inner ear of deaf individuals. Dr Loizou
expects this technology to have a profound impact on the life of hearing
impaired people with the PDA processor acting as a speech processor, a PC,
a phone, an assistive listening device, a GPS device, an Internet browser
and a music player all integrated into one device. Dr Loizou said the new
interface he hopes to develop will allow PDAs to process acoustic signals,
such as speech, through a microphone that is worn behind an individual’s
ear. The signal would then be transmitted wirelessly into a cochlear implant
in the inner ear. Technology currently exists to transmit sounds to cochlear
implant users, but it is costly and relies on custom-made speech processors.
Replacing the speech processors with PDAs will make the technology more affordable,
and the flexibility of PDAs will make the technology more accessible. - University
of Dallas Texas News ,
USA, 30th March 2006
Hybrid Cochlear Implants Combine the Best of Bionics with Regular Hearing
Aids
Researchers in Iowa (USA) are developing the next generation of "hybrid
implant" to combine the best of bionics with regular hearing aids
for age-related hearing loss. This will allow cochlear implants to
be a viable option for partial hearing loss. Bruce Gantz, an otolaryngologist
at the University of Iowa invented the hybrid model and it is now being
tested at 26 medical centres around America. Cochlear implants turn
sound into electrical impulses that directly activate the hearing nerve,
allowing the deaf to hear. They've proven particularly beneficial for
deaf babies and young children, dramatically improving their ability
to learn to speak and comprehend language normally. But for people
who aren't completely deaf, cochlear implants have a big drawback where
snaking the electrode deep into the cochlea tends to destroy any functional
remaining hair cells in the inner ear. For example, if your only problem
was detecting high-frequency sounds, a regular cochlear implant would
also destroy your existing ability to hear low-frequency sounds. Gantz's
solution was to make the electrode shorter, so it only substitutes
for the hearing that's already lost, paired with a regular hearing
aid to amplify the remaining low-frequencies. So far, about 60 patients
have received the hybrid implant (manufactured by Cochlear Americas)
and of these 10 have had it for more than a year. On standard hearing
tests these patients understand 70% of words a year after the implant
- up from 25% before the surgery. In addition the comprehension seems
to continue improve as the brain rewires itself to better recognize
the electronic signals. - Contra
Costa Times (CA), USA Research, 18th March 2006
February
2006
Preserving Hearing with Ear Tumour Removal
A new study from the University of Michigan Medical School
(USA), by Prof. H. Alexander Arts and colleagues, found high
rates of success
at preserving
patients' hearing when a particular type of procedure was used to remove
the tumours (acoustic neuromas or vestibular schwannomas). The study examined
73 patients with acoustic neuromas who were operated on between 1999 and
2005 using a procedure known as the middle cranial fossa (MCF) approach.
Of the people in the study who had useful hearing before the surgery, about
three-quarters retained a level of useful hearing after their tumours were
removed. There are several surgical approaches for removing acoustic neuromas.
Only two, the "MCF" approach and the "suboccipital" approach,
allow for the possibility of hearing preservation. The suboccipital approach
comes from behind the ear, and the MCF approach is from above the ear. Smaller
tumours usually can be removed much more easily and with less chance of injury
to the hearing nerve using the MCF approach. Since the more widespread use
of the MCF approach, and because tumours are now being diagnosed when they
are smaller due to improved MRI imaging techniques, hearing preservation
rates have been improving. The results presented in this study represent
the highest hearing preservation rates published to date. This work was published
in the February 2006 issue of the journal Otology & Neurotology. - EurekAlert,
USA research, 28th February 2006
US Soldiers' Suffer from Serious Hearing Damage
A new US army study suggests that thousands of american soldiers sent to Iraq
have suffered serious hearing damage from bombs, rocket explosions and other
combat noise. Many of these injuries could have been prevented but earplugs
have been in short supply and the army has not told soldiers enough about
the noise risks of battle or monitored them adequately for hearing damage.
The US army is currently operating with only half the number of audiologists
in the 1990s (when there were about 70) and there is currently only one audiologist
deployed to Iraq at any given time. Auditory problems are the third most
common veterans' disability. In this study about 6% of the soldiers studied
suffered "acoustic trauma," often resulting from a single loud
noise like a bomb blast, 2% percent had broken eardrums, which often heal
but in the meantime leave soldiers vulnerable to inner ear infections in
unsanitary battlefield environments, and in about 16% of those studied, the
report found, the hearing losses were likely to affect their performance
in combat. By comparing the hearing of those who had served in Iraq with
those who didn't it was found that soldiers sent to battle zones were 52.5
times more likely to suffer auditory damage. This report was published in
the American Journal of Audiology (February 2006). The lead author for this
study is Thomas M. Helfer (hearing specialist and retired Army reservist).
- Seattle
Times, USA, 22nd February 2006
Hormone Linked To Good Hearing in Older People
Researchers from the International Center for Hearing and Speech
Research - ICHSR (University of Rochester, N.Y.,USA) have linked the
hormone, aldosterone, to the quality of hearing as we age. They found
that the more of the hormone older people had in their bloodstream,
the better their hearing was, and the less of the hormone, the worse
their hearing was. This hormone is known to play a role in controlling
levels of two crucial signaling chemicals in the nervous system; potassium
and sodium. For nerves to send signals and work effectively, potassium
and sodium must be in precise proportion, without any disruption in
the molecular channels or gates through which they move. Levels of
potassium are particularly crucial in the sensitive inner ear, where
fluid rich in potassium plays a central role in converting sounds into
signals that the nervous system recognizes. In the study 47 healthy
men and women between the ages of 58 and 84 were examined. It was found
that people with severe hearing loss had on average about half as much
aldosterone in their bloodstream as their counterparts with normal
hearing. The researchers noted, however, that the levels of aldosterone
found in all the participants is considered normal, and that no patients
or physicians should consider altering aldosterone levels without more
research. Robert D. Frisina, Ph.D. (Professor of Otolaryngology, University
of Rochester Medical Center) said, "We know that potassium levels
in the inner ear seem to decrease as we age and that these falling
levels play a role in age-related hearing loss, and we also know that
blood levels of aldosterone generally decrease with age. We found a
direct link between blood levels of aldosterone and the ability of
people to hear normally as they age. Depressed hormone levels may hurt
hearing both in the inner ear and the part of the brain used for hearing.
More research is needed, however, to understand the precise role that
aldosterone plays, for instance, whether it's a cause of failed hearing,
or whether it's symptomatic. Before we understand the issue more fully,
people should not worry about their aldosterone levels or look to boost
the amount in their bloodstream." This work was first published
in the November 2005 issue of the journal Hearing Research, and this
week at the annual international meeting of the Association for Research
in Otolaryngology in Baltimore, the team presented its latest results
showing just how important potassium regulation is to age-related hearing
loss. - Medical
News Today, USA research, 18th February 2006
Siren Noise to Annoy Teenagers
A new high frequency sound emitting device, called the Mosquito
is now available in the UK, as a deterrent to disperse unruly teenagers.  The
device makes an ear-splitting sound which can only generally be
heard by those under the age of 20. Rochdale council in Manchester
(UK) is one of the first local authorities to adopt the pioneering
device. The Mosquito was invented by security expert Howard Stapleton.
Mr Stapleton, said: "The device emits a high frequency pulse
that is barely audible to anyone over 20 because as we get older
we suffer progressive hearing loss due to our noisy environment
and the structure of our ear changes. The 20-year-old mark is not
absolute. But 90 per cent of people under 20 will be able to hear
it and 90 per cent of people over 30 won't." Mr Stapleton
added: "It has been patented and tested by the National Physics
Laboratory. They've certified that it won't cause hearing damage
even if someone can bear to listen to it for sustained periods." - Manchester
Evening News, UK, 15th February 2006 (there
is also a related article in The
Guardian Newspaper - 15.2.06) |
Hearing-Aid Suppliers Tap into Gadget Market
Many people wouldn't be caught dead wearing a hearing aid, even if they've
lost enough hearing to need one. So hearing-aid suppliers are trying to broaden
their appeal with audiological products for all ages with things such as
custom-molded earpieces for teenage iPod junkies along with Bluetooth cell
phone headsets for their car-commuting mums and dads, to name a few. One
gizmo (the Eli) consists of a hearing-aid plug-in module that adds Bluetooth
wireless-networking capabilities. - Bradenton
Herald, USA, 5th February 2006
New Cochlear Implant Could Improve Hearing
A new ribbon-like cochlear implant has been developed by Kensall
Wise and colleagues at the NSF Engineering Research Center for Wireless
Integrated Microsystems (University of Michigan, USA).  This
could greatly improve hearing for profoundly deaf patients, and simplify
insertion to help surgeons minimise the damage to healthy ear tissue.
The researchers made the implant using thin-film electrode sites that
directly stimulate the auditory nerve. This device may be available
commercially in four to five years. In comparison to this new implant
the currently available technology is bulky, difficult for surgeons
to insert, and doesn't allow a great range of perceived frequencies.
The present implants use electrodes formed from a bundle of wires fed
into the snail-shaped cochlea of the inner ear, but difficulties in
inserting such devices make it tough to achieve the deep insertion
needed to stimulate lower-frequency sounds, and collisions with the
cochlear wall can damage any residual hearing that still exists. In
current technology, each implant only has 16 to 22 stimulating sites
along its length. By contrast, the new implant will host up to 128
stimulating sites which will mean a greater tonal range and better
frequency perception and the implant's flexibility will minimise damage
to existing hearing. The ribbon film technology lets researchers embed
other functions in the implant, such as position sensors that allow
surgeons to watch the implant's progress on a monitor as they're feeding
it into the cochlea. Kensall Wise said that, "Eventually the idea
is to be able take the signals from the position sensors and use them
to control actuators in an insertion tool, so that the electrode array
can achieve deep insertion and navigate around any obstacles in its
path." The implants are made in the same way as integrated circuits
are, which means they can be made in batch. This research was to be
presented at the International Solid-State Circuits Conference (ISSCC)
in San Francisco, USA (6th February 2006). - aud.org.uk,
USA Research, 6th February 2006 (news source: University
of Michigan News press release - 6.2.06)
Apple Sued for Potential iPod Hearing Loss
An iPod owner in Louisiana, USA has taken out a law suite against Apple Computers.
He claims that Apple's iPod music player can cause hearing loss in people
who use it. The devices can produce sounds of more than 115 decibels. This
is a volume which can damage the hearing of a person exposed to the sound
for more than 28 seconds per day. Apple was forced to pull the iPod from
store shelves in France and upgrade software on the device to limit sound
to 100 decibels, but the company has not followed suit other countries such
as the United States. - MSNBC
News (USA), 2nd February 2006
January
2006
Study Shows Drops are Better than Pills for Chronic Ear Infections
A new review of available research literature concluded that short course of
quinolone antibiotic ear drops were more effective at drying the ear than
oral or injected antibiotics at treating middle ear infections. The authors
noted that chronically discharging ears associated with underlying persistent
eardrum perforations, a condition called chronic suppurative otitis media
(CSOM), are a common cause of preventable hearing impairment. Untreated CSOM
can lead to damage of the small sound-transmitting bones in the middle ear,
resulting in permanent hearing loss. When this occurs in children, they can
suffer impaired language and speech development. The authors said there was
not enough available information for them to assess the effectiveness of
topical non-quinolone antibiotics that do not contain steroids, or of antiseptic
treatments, compared to oral or injected antibiotics. This review appears
in the latest update of The Cochrane Library. - Health
Day News, 30th January 2006
Gene Determines Whether Earwax is Wet or Dry
A international team of 39 scientists, led by researchers from the Department
of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences
(Japan), discovered the reason for the differences in the type of ear wax
found in different people. It was found that whether the earwax was wet or
dry was determined by a mutation in a single gene called ABCC1. Thirty-three
populations across the world were studied and it was found that ethnicity
affects which form of the gene people have, and therefore their earwax type.
Dry earwax is seen in up to 95% of East Asians, but no more than 3% of people
of European and African origin. In both Europeans and Africans, the wet type
completely dominates. This gene ABCC11 controls the behaviour of a cell channel
controlling the flow of earwax-altering molecules. The scientists, led by
Koh-ichiro Yoshiura, suggest that a change in the channel probably first
occurred in North-East Asia, and subsequently spread throughout Asia, as
well as to native Americans and Inuit people with Asian origins. They add
that, "the implications of earwax remain unknown". But they suggest: "Insect
trapping, self-cleaning and prevention of dryness of the external auditory
canal are its plausible functions." - BBC
News (UK), Japanese / International research, 30th January
2006 (This is published in the February 2006 issue of the journal Nature
Genetics. The abstract of
the paper is given here - editorial)
MRIs Better at Diagnosing Needs for Cochlear Implants
A research team led by Dr Peter Roland (professor and chairman
of otolaryngology, UT Southwestern, USA) has found that magnetic resonance
imaging (MRI) offers better diagnostic information for cochlear ear
implants  than
the more commonly used high-resolution computed tomography. This is
the first head-to-head comparison of these two techniques. It was found
that 30% of patients evaluated had abnormalities on MRI which would
not have seen on CT, whereas there where no additional findings using
CT which would not have seen on MRI. Some of the specifics found can
be used to help determine which surgical technique is used, the specific
electrode arrays employed and can impact in which ear the cochlear
implant is placed. On average, testing and anaesthesiology costs for
MRIs were found to be 40 - 50% higher than those associated with CTs.
These results are reported online in the Journal Otology & Neurotology.
- UT
Southwestern Medical Center News, USA Research, 11th January
2006
American Military Pilots Share Technology with Rock Stars to Protect
Hearing
The same kind of earplugs sold to rock bands are now starting to be used by
U.S. military  pilots
to protect hearing, muffle cockpit noise and ease communications. The new silicon
earplugs were at first only used by the aircraft maintenance workers, but they
are now being used for pilots, since they were found to be so effective. Unlike
commercial aircraft, military planes usually have no insulation in the cockpit
to help muffle engine and wind noise and the fans that cool cockpit equipment
can be loud. The new ear plugs are made of silicon, with speakers implanted
inside. Each plug is designed to fit the ears of individual pilots and they
have small vents that relieve pressure created with changes in altitude that
can rupture eardrums. These ear plugs cost more than $200 a pair, where as
the old foam plugs cost a tiny fraction. However the old plugs were thrown
away after one use. - MSNBC
News  ,
USA, 11th January 2006
Loud Noises Linked to Acoustic Neuroma
Research conducted at the Ohio State University (USA) showed that
people regularly exposed to loud noise over several years are more
likely to develop a benign tumour called an acoustic neuroma that causes
hearing loss. The history of exposure to loud music was examined for
146 people with acoustic neuroma and 564 people without the tumour.
It was found that people exposed to loud music were 2.5 times more
likely to develop acoustic neuroma, while those exposed to machines,
power tools and/or construction were 1.8 times more likely to develop
the tumour exposure to motors increased risk by 1.3 times while regular
exposure to screaming children, sports events and/or bars and restaurants
increased the risk by 1.4 times. The number of years that a person
was exposed to any kind of loud noise also influenced risk. Five years
of regular exposure to loud noise was found to be associated with a
1.5 times increased risk of acoustic neuroma. The study also found
that the use of hearing protection offered significant protection against
developing this kind of tumour The findings from this work appear in
the current online edition of the American Journal of Epidemiology
and will appear in the 15.2.06 print issue of the journal. - Health
Day News, USA Research, 6th January 2006 (see also the EurekAlert news,
4.1.06)
Rock Star Blames his Hearing Loss on Headphone Use
Pete Townshend lead gitarist for the rock group 'The Who' at 60 years old is
now struggling with irreparable hearing loss. Mr Townshend blames his hearing
loss on a lifetime spent using headphones in recording studios and he says
that he fears for the 'iPod generation'. Others in the music world who have
also witnessed premature hearing problems include Phil Collins, Neil Young,
Sting, Mick Fleetwood and the Beatles producer George Martin. This however
is not confined to just rock / pop musicans as a third of orchestral musicians
also suffer from hearing loss.- BBC
News, UK, 5th January 2006
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