Contact Information:
Mary Leach
Mary_Leach@meei.harvard.edu
Massachusetts Eye and Ear Infirmary



Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości.

PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION
RSS - Press News Release
Add Press Release

Researchers turn current sound-localization theories 'on their ear'

Mass. Eye and Ear scientists challenge the two dominant theories of how people localize sounds


2013-12-03
(Press-News.org) Contact information: Mary Leach
Mary_Leach@meei.harvard.edu
Massachusetts Eye and Ear Infirmary
Researchers turn current sound-localization theories 'on their ear' Mass. Eye and Ear scientists challenge the two dominant theories of how people localize sounds BOSTON (Dec. 3, 2013) – The ability to localize the source of sound is important for navigating the world and for listening in noisy environments like restaurants, an action that is particularly difficult for elderly or hearing impaired people. Having two ears allows animals to localize the source of a sound. For example, barn owls can snatch their prey in complete darkness by relying on sound alone. It has been known for a long time that this ability depends on tiny differences in the sounds that arrive at each ear, including differences in the time of arrival: in humans, for example, sound will arrive at the ear closer to the source up to half a millisecond earlier than it arrives at the other ear. These differences are called interaural time differences. However, the way that the brain processes this information to figure out where the sound came from has been the source of much debate.

A recent paper by Mass. Eye and Ear/Harvard Medical School researchers in collaboration with researchers at the Ecole Normale Superieure, France, challenge the two dominant theories of how people localize sounds, explain why neuronal responses to sounds are so diverse and show how sound can be localized, even with the absence of one half of the brain. Their research is described on line in the journal eLife.

"Progress has been made in laboratory settings to understand how sound localization works, but in the real world people hear a wide range of sounds with background noise and reflections," said Dan F. M. Goodman, lead author and post-doctoral fellow in the Eaton-Peabody Laboratories at Mass. Eye and Ear, Harvard Medical School. "Theories based on more realistic environments are important. The theme of the paper is that previous theories about this have been too idealized, and if you use more realistic data, you come to an entirely different conclusion."

"Two theories have come to dominate our understanding of how the brain localizes sounds: the peak coding theory (which says that only the most strongly responding brain cells are needed), and the hemispheric coding theory (which says that only the average response of the cells in the two hemispheres of the brain are needed)," Goodman said. "What we've shown in this study is that neither of these theories can be right, and that the evidence they presented only works because their experiments used unnatural/idealized sounds. If you use more realistic, natural sounds, then they both do very badly at explaining the data."

Researchers showed that to do well with realistic sounds, one needs to use the whole pattern of neural responses, not just the most strongly responding or average response. They showed two other key things: first, it has long been known that the responses of different auditory neurons are very diverse, but this diversity was not used in the hemispheric coding theory.

"We showed that the diversity is essential to the brain's ability to localize sounds; if you make all the responses similar then there isn't enough information, something that was not appreciated before because if one has unnatural/idealized sounds you don't see the difference" Goodman said.

Second, previous theories are inconsistent with the well-known fact that people are still able to localize sounds if they lose one half of our brain, but only sounds on the other side (i.e. if one loses the left half of the brain, he or she can still localize sounds coming from the right), he added.

"We can explain why this is the case with our new theory," Goodman said.

### The full study, including a description of the research methods used, is available at http://elife.elifesciences.org/. A full list of authors is also included in the paper.

About Massachusetts Eye and Ear Mass. Eye and Ear clinicians and scientists are driven by a mission to find cures for blindness, deafness and diseases of the head and neck. After uniting with Schepens Eye Research Institute, Mass. Eye and Ear in Boston became the world's largest vision and hearing research center, offering hope and healing to patients everywhere through discovery and innovation. Mass. Eye and Ear is a Harvard Medical School teaching hospital and trains future medical leaders in ophthalmology and otolaryngology, through residency as well as clinical and research fellowships. Internationally acclaimed since its founding in 1824, Mass. Eye and Ear employs full-time, board-certified physicians who offer high-quality and affordable specialty care that ranges from the routine to the very complex. U.S. News & World Report's "Best Hospitals Survey" has consistently ranked the Mass. Eye and Ear Departments of Otolaryngology and Ophthalmology among the top hospitals in the nation.

ELSE PRESS RELEASES FROM THIS DATE:

New thermoelectronic generator

2013-12-03
New thermoelectronic generator Highly efficient new design, described in 'Journal of Renewable and Sustainable Energy,' converts heat and solar energy into electricity WASHINGTON D.C. Dec. 3, 2013 -- Through a process known as thermionic conversion, heat ...

UK review examines gender differences in COPD patients

2013-12-03
UK review examines gender differences in COPD patients LEXINGTON, Ky. (Dec. 3, 2013) — A new study review authored by the University of Kentucky's Dr. David Mannino examines the gender differences in the prevalence, pathophysiology, and clinical presentation of ...

Unlikely collaboration leads to discovery of 'gender-bending' plant

2013-12-03
Unlikely collaboration leads to discovery of 'gender-bending' plant Bucknell professor Chris Martine never expected to be working with his mentor on identifying a new wild eggplant in Australia, especially since Martine's former colleague passed away years ago Bucknell ...

Neurofeedback tunes key brain networks, improving subjective well-being in PTSD

2013-12-03
Neurofeedback tunes key brain networks, improving subjective well-being in PTSD Pioneering research conducted at Western University (London, Canada) points to a promising avenue for the treatment of post-traumatic stress disorder (PTSD): utilising neurofeedback ...

Majority of Americans believe another government shutdown likely in coming months

2013-12-03
Majority of Americans believe another government shutdown likely in coming months Last government shutdown harmful to medical research ALEXANDRIA, Va.—December 3, 2013—Nearly two-thirds (65%) of Americans say it's likely there will be another government shutdown ...

Manufacturing a new gut to treat GI diseases

2013-12-03
Manufacturing a new gut to treat GI diseases Researchers develop way to grow and control maturation of intestinal stem cells, findings pave new ways to treat gastrointestinal disorders Boston, MA – For those living with gastrointestinal ...

Do sports concussions really cause chronic traumatic encephalopathy?

2013-12-03
Do sports concussions really cause chronic traumatic encephalopathy? Study finds little evidence to support link MAYWOOD, Ill. – It's been widely reported that football and other contact sports increase the risk of a debilitating neurological condition called ...

Obesity, smoking increase risk after immediate breast reconstruction with implants

2013-12-03
Obesity, smoking increase risk after immediate breast reconstruction with implants New risk-scoring tool allows surgeons to better counsel and potentially change an operative plan for women at higher risk for implant failure after mastectomy, Journal of the ...

NASA sees thirty-third tropical depression form in Northwestern Pacific

2013-12-03
NASA sees thirty-third tropical depression form in Northwestern Pacific The Northwestern Pacific Ocean tropical cyclone season continues with the formation of the thirty-third tropical depression today, December 3, 2013.Two NASA satellites provided a look at the ...

Protein in prostate biopsies signals increased cancer risk

2013-12-03
Protein in prostate biopsies signals increased cancer risk Finding may help clinicians decide which men, with an aberrant biopsy, could benefit from additional future biopsy screenings NEW YORK (December 3, 2013) -- Researchers from Weill Cornell Medical ...

LAST 30 PRESS RELEASES:

How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[Press-News.org] Researchers turn current sound-localization theories 'on their ear'
Mass. Eye and Ear scientists challenge the two dominant theories of how people localize sounds
Press-News.org is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.