For Hearing Parts of Brain, Deafness Reorganizes Sensory Inputs, Not Behavioral Function

ScienceDaily (May 10, 2011) — "The part of the brain that uses hearing to determine sound location is reorganized in deaf animals to locate visual targets, according to a new study by a team of researchers from Virginia Commonwealth University and the University of Western Ontario in Canada.These findings propose a new theory for cross-modal plasticity: loss of one sensory modality is substituted by another while maintaining the original function of the brain region.
It is known that persons who have suffered major sensory loss, such as deafness, show compensatory, or even superior performance in the remaining senses. This occurs through a process of cross-modal plasticity, where loss of one sensory modality is replaced by the remaining senses. But researchers have not known how the brain region vacated by one sensory modality selects its sensory replacement -- until now.
In a study, published online the week of May 9 in the Early Edition of the Proceedings of the National Academy of Sciences, the team first examined the region of auditory cortex in hearing adult animals that responded to auditory stimuli and controlled orienting and localization behaviors in response to sounds."

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Americans Living with Disability and Their Technology Profile

Pew Internet (Jan. 21, 2011) According to a national survey conducted in September 2010, 27% of American adults live with a disability that interferes with activities of daily living, including:

* 15% of American adults who say they have serious difficulty walking or climbing stairs.
* 11% of American adults who say that, because of a physical, mental, or emotional condition, they have serious difficulty concentrating, remembering, or making decisions.
* 9% of American adults who say they have serious difficulty hearing.
* 8% of American adults who say that, because of a physical, mental, or emotional condition, they have difficulty doing errands alone such as visiting a doctor’s office or shopping.
* 7% of American adults who say they are blind or have serious difficulty seeing, even when wearing glasses.
* 3% of American adults who say they have trouble dressing or bathing.

Americans living with disability are more likely than other adults to live in lower-income households: 46% of adults with a disability live in households with $30,000 or less in annual income, compared with 26% of adults who report no disabilities and live in households with that level of income.

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Growth-Factor Gel Shows Promise as Hearing-Loss Treatment

ScienceDaily (Nov. 26, 2010) — A new treatment has been developed for sudden sensorineural hearing loss (SSHL), a condition that causes deafness in 40,000 Americans each year, usually in early middle-age. Researchers writing in the open access journal BMC Medicine describe the positive results of a preliminary trial of insulin-like growth factor 1 (IGF1), applied as a topical gel.

Takayuki Nakagawa, from Kyoto University, Japan, worked with a team of researchers to test the gel in 25 patients whose SSHL had not responded to the normal treatment of systemic gluticosteroids. He said, "The results indicated that the topical IGF1 application using gelatin hydrogels was safe, and had equivalent or superior efficiency to the hyperbaric oxygen therapy that was used as a historical control; this suggests that the efficacy of topical IGF1 application should be further evaluated using randomized clinical trials."

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New Norwegian Earplug Solution to a Deafening Problem

ScienceDaily (Aug. 20, 2010) Some 600 cases of noise-induced hearing impairment are reported by the Norwegian petroleum industry every year. A new, intelligent earplug is now set to alleviate the problem.

Norway's largest company, Statoil ASA, is taking the problems associated with noise exposure seriously. Over the course of four years the international energy company has led efforts to further develop an existing combined hearing protection and communication product for use on offshore platforms.

World's most advanced hearing protection device
A microphone on the outside of the new "offshore" version of the QUIETPRO earplug picks up ambient sounds. The sound is digitally processed, and unwanted loud noises are filtered out before the sound is sent to a speaker inside the earplug. Users can adjust the level of ambient sound, as desired.

A microphone on the inside of the earplug picks up speech signals through the skull. This means that users do not have to have a microphone in front of their mouth, as is the case with the ear protection devices currently used on most offshore platforms. Another advantage is that the microphone inside the ear does not pick up background noise in the way that a microphone in front of the mouth does.


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Aiming to Cure Deafness, Scientists First to Create Functional Inner-Ear Cells

ScienceDaily (May 14, 2010) — "Deep inside the ear, specialized cells called hair cells detect vibrations in the air and translate them into sound. Ten years ago, Stefan Heller, PhD, professor of otolaryngology at the Stanford University School of Medicine, came up with the idea that if you could create these cells in the laboratory from stem cells, it would go a long way toward helping scientists understand the molecular basis of hearing in order to develop better treatments for deafness."

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Kids With Hearing Loss in One Ear Fall Behind in Language Skills, Study Finds

ScienceDaily (May 5, 2010) — "By the time they reach school age, one in 20 children have hearing loss in one ear. That can raise significant hurdles for these children, say the results of a new study at Washington University School of Medicine in St. Louis, because loss of hearing in one ear hurts their ability to comprehend and use language."

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Regular Analgesic Use Increases Hearing Loss in Men, Study Finds

ScienceDaily (Mar. 1, 2010) — In a study published in the March 2010 issue of The American Journal of Medicine, researchers determined that regular use of aspirin, acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) increases the risk of hearing loss in men, particularly in younger men, below age 60.

Hearing loss is the most common sensory disorder in the US, afflicting over 36 million people. Not only is hearing loss highly prevalent among the elderly, but approximately one third of those aged 40-49 years already suffer from hearing loss. Even mild hearing loss can compromise the ability to understand speech in the presence of background noise or multiple speakers, leading to social isolation, depression, and poorer quality of life.

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Word Learning Better in Deaf Children Who Receive Cochlear Implants by Age 13 Months

ScienceDaily (Mar. 1, 2010) — Learning words may be facilitated by early exposure to auditory input, according to research presented by the Indiana University School of Medicine at the American Association for the Advancement of Science Annual Meeting in San Diego, Feb. 18-22. A growing body of evidence points to the importance of early auditory input for developing language skills. Indiana University Department of Otolaryngology researchers have contributed to that evidence with several projects, including their study involving 20 deaf children (22- to 40-months-old and 12 to 18 months after cochlear implantation) and 20 normal hearing children (12- to 40-months of age) that was presented Feb. 21 at the AAAS meeting. The study's principal author, Derek Houston, Ph.D., associate professor and Philip F. Holton Scholar at the IU School of Medicine, said the study found that deaf children's word-learning skills were strongly affected by their early auditory experience.

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Auditory Illusion: How Our Brains Can Fill in the Gaps to Create Continuous Sound

ScienceDaily (Nov. 27, 2009) — It is relatively common for listeners to "hear" sounds that are not really there. In fact, it is the brain's ability to reconstruct fragmented sounds that allows us to successfully carry on a conversation in a noisy room. Now, a new study helps to explain what happens in the brain that allows us to perceive a physically interrupted sound as being continuous. The research, published by Cell Press in the November 25 issue of Neuron provides fascinating insight into the constructive nature of human hearing.

"In our day-to-day lives, sounds we wish to pay attention to may be distorted or masked by background noise, which means that some of the information gets lost. In spite of this, our brains manage to fill in the information gaps, giving us an overall 'image' of the sound," explains senior study author, Dr. Lars Riecke from the Department of Cognitive Neuroscience at Maastricht University in The Netherlands. Dr. Riecke and colleagues were interested in unraveling the neural mechanisms associated with this auditory continuity illusion, where a physically interrupted sound is heard as continuing through background noise.

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Scientists Show How Tiny Cells Deliver Big Sound In Cochlea

Medical illustration of the human osscous labyrinth, from "1870 Gray's Anatomy Descriptive And Surgical Book - First Edition". (Credit: iStockphoto/Mark Strozier)

ScienceDaily (Oct. 23, 2009) — Deep in the ear, 95 percent of the cells that shuttle sound to the brain are big, boisterous neurons that, to date, have explained most of what scientists know about how hearing works. Whether a rare, whisper-small second set of cells also carry signals from the inner ear to the brain and have a real role in processing sound has been a matter of debate.

Now, reporting on rat experiments in the October 22 issue of Nature, a Johns Hopkins team says it has for what is believed to be the first time managed to measure and record the elusive electrical activity of the type II neurons in the snail-shell-like structure called the cochlea. And it turns out the cells do indeed carry signals from the ear to the brain, and the sounds they likely respond to would need to be loud, such as sirens or alarms that might be even be described as painful or traumatic.

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Cochlear Implants Reduce Delay Suffered By Deaf Children In Language Acquisition, Study Shows

ScienceDaily (Oct. 19, 2009) — A multidisciplinary group at Malaga University, headed by Ignacio Moreno-Torres, is collecting information on the milestones that mark the development of deaf children fitted with a Cochlear Implant (CI) and studying to what extent the social and family environment affects this development. This research is funded with 101,000 euro by the Andalusian Regional Ministry of Innovation.

The researchers have observed in this first year of the study that, three months after receiving the implant all the children showed improvement in their perception and ability to detect sounds around them. Children quickly learn that the CI is a device that allows them to hear and if it is deactivated they protest or make gestures asking that it be switched back on.

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Men Nearly Three Times As Likely To Develop Noise-induced Hearing Loss

ScienceDaily (Oct. 6, 2009) — A comprehensive study of the prevalence and risk factors for noise-induced hearing loss (NIHL) show that men, especially those who are white and married, are significantly more at risk than women, according to new research presented at the 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting & OTO EXPO, in San Diego, CA.

The study, which analyzed the audiometric testing data from 5,290 people between the ages of 20 and 69 years indicates that more than 13 percent of subjects suffer from NIHL, which would correspond with approximately 24 million Americans suffering from the ailment. The strongest association was of gender, where men are 2.5 times more likely to develop NIHL than women. Among that group, married white (non-Hispanic) men represent the highest risk group for developing NIHL.

NIHL is a preventable and increasingly prevalent disorder that results from exposure to high-intensity sound, especially over a long period of time.

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Genetic Cause For Type Of Deafness Identified; Discovery Could Lead To New Therapies For Progressive Hearing Loss

ScienceDaily (Sep. 4, 2009) — A team led by scientists from The Scripps Research Institute has discovered a genetic cause of progressive hearing loss. The findings will help scientists better understand the nature of age-related decline in hearing and may lead to new therapies to prevent or treat the condition.

The findings were published the September 3, 2009, in an advance, online issue of the American Journal of Human Genetics, a publication of Cell Press.

"It is thought that mutations in several hundred genes can lead to deafness," said team leader Ulrich Mueller, a professor in the Department of Cell Biology and member of the Skaggs Institute for Chemical Biology at Scripps Research. "However, for many forms of deafness, we don't know what effects the genes have. In this new research, we have linked a previously uncharacterized gene to deafness, first in mice and then in humans."

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Taking Up Music So You Can Hear

(Credit: iStockphoto)

ScienceDaily (Aug. 27, 2009) — Anyone with an MP3 device -- just about every man, woman and child on the planet today, it seems -- has a notion of the majesty of music, of the primal place it holds in the human imagination.

But musical training should not be seen simply as stuff of the soul -- a frill that has to go when school budgets dry up, according to a new Northwestern University study.

The study shows that musicians -- trained to hear sounds embedded in a rich network of melodies and harmonies -- are primed to understand speech in a noisy background, say in a restaurant, classroom or plane...

The findings strongly support the potential therapeutic and rehabilitation use of musical training to address auditory processing and communication disorders throughout the life span.

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Light Shed On Brain's Mechanism Responsible For Processing Of Speech

ScienceDaily (Aug. 14, 2009) — Researchers from the Hebrew University of Jerusalem have succeeded for the first time in devising a model that describes and identifies a basic cellular mechanism that enables networks of neurons to efficiently decode speech in changing conditions.

The research may lead to the upgrading of computer algorithms for faster and more precise speech recognition as well as to the development of innovative treatments for auditory problems among adults and young people.

Our brain has the capability to process speech and other complex auditory stimuli and to make sense of them, even when the sound signals reach our ears in a slowed, accelerated or distorted manner.

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Hearing Aids: New Software Makes It Easier To Hear The Words Beneath The Noise

ScienceDaily (Aug. 6, 2009) — Hearing aids and cochlear implants act as tiny amplifiers so the deaf and hard-of-hearing can make sense of voices and music. Unfortunately, these devices also amplify background sound, so they're less effective in a noisy environment like a busy workplace or café.

But help is on the way. Prof. Miriam Furst-Yust of Tel Aviv University's School of Electrical Engineering has developed a new software application named "Clearcall" for cochlear implants and hearing aids which improves speech recognition for the hard-of-hearing by up to 50%.

"Hearing-impaired people have a real problem understanding speech," says Prof. Furst-Yust. "Their devices may be useful in a quiet room, but once the background noise levels ramp up, the devices become less useful. Our algorithm helps filter out irrelevant noise so they can better understand the voices of their friends and family."

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Better Than A Hearing Aid? Better Hearing With Bone Conducted Sound

The red marking shows bone conduction from one's own voice and from an implanted vibrator. The blue marking shows air conduction from one's own voice. (Credit: Image courtesy of The Swedish Research Council)

ScienceDaily (July 9, 2009) — New technology to hear vibrations through the skull bone has been developed at Chalmers University of Technology. Besides investigating the function of a new implantable bone conduction hearing aid, Sabine Reinfeldt has studied the sensitivity for bone conducted sound and also examined the possibilities for a two-way communication system that is utilizing bone conduction in noisy environments.

A new Bone Conduction Implant (BCI) hearing system was investigated by Sabine Reinfeldt. "This hearing aid does not require a permanent skin penetration, in contrast to the Bone-Anchored Hearing Aids (BAHAs) used today," she said.

Measurements showed that the new BCI hearing system can be a realistic alternative to the BAHA.

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Hearing Manipulated By Electronics

ScienceDaily (July 7, 2009) — An implanted electronic ion pump in organic material can be used to carry signals to specific cells in the nervous system and in this way treat various illnesses. In a unique study, researchers at Linköping University (LiU) and Karolinska Institutet (KI) have used the pumps to successfully manipulate the hearing in laboratory animals.

The technique which is described in an article in the journal Nature Materials represents a breakthrough for the machine-to-brain interface, with opportunities for greater symbiosis between electronics and biological systems.

“In the future we envisage a wirelessly controlled and permanent implant”, says Magnus Berggren, Professor of Organic Electronics at LiU and one of the authors of the article.

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Need Something? Talk To My Right Ear

(Credit: iStockphoto/Artsem Martysiuk)

ScienceDaily (June 23, 2009) — We humans prefer to be addressed in our right ear and are more likely to perform a task when we receive the request in our right ear rather than our left. In a series of three studies, looking at ear preference in communication between humans, Dr. Luca Tommasi and Daniele Marzoli from the University "Gabriele d'Annunzio" in Chieti, Italy, show that a natural side bias, depending on hemispheric asymmetry in the brain, manifests itself in everyday human behavior.

One of the best known asymmetries in humans is the right ear dominance for listening to verbal stimuli, which is believed to reflect the brain's left hemisphere superiority for processing verbal information. However, until now, the majority of studies looking at ear preference in human communication have been controlled laboratory studies and there is very little published observational evidence of spontaneous ear dominance in everyday human behavior.

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Age-related Difficulty Recognizing Words Predicted By Brain Differences

ScienceDaily (May 14, 2009) — Older adults may have difficulty understanding speech because of age-related changes in brain tissue, according to new research in the May 13 issue of The Journal of Neuroscience. The study shows that older adults with the most difficulty understanding spoken words had less brain tissue in a region important for speech recognition. The findings may help explain why hearing aids do not benefit all people with age-related hearing difficulties.

Although some hearing loss can be a normal part of aging, many older adults complain about difficulty understanding speech, especially in challenging listening conditions like crowded restaurants. Research has suggested that this decline in speech recognition is independent of hearing loss.

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