Featured Research

from universities, journals, and other organizations

Ability To Listen To Two Things At Once Is Largely Inherited, Says Twin Study

Date:
July 17, 2007
Source:
NIH/National Institute on Deafness and Other Communication Disorders
Summary:
Your ability to listen to two things at once is an important communication skill that's heavily influenced by your genes. The finding may help researchers better understand a broad and complex group of disorders called auditory processing disorders.

Your ability to listen to a phone message in one ear while a friend is talking into your other ear--and comprehend what both are saying--is an important communication skill that's heavily influenced by your genes, say researchers of the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health.

Related Articles


The finding, published in the August 2007 issue of Human Genetics, may help researchers better understand a broad and complex group of disorders--called auditory processing disorders (APDs)--in which individuals with otherwise normal hearing ability have trouble making sense of the sounds around them.

"Our auditory system doesn't end with our ears," says James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. "It also includes the part of our brain that helps us interpret the sounds we hear. This is the first study to show that people vary widely in their ability to process what they hear, and these differences are due largely to heredity."

The term "auditory processing" refers to functions performed primarily by the brain that help a listener interpret sounds. Among other things, auditory processing enables us to tell the direction a sound is coming from, the timing and sequence of a sound, and whether a sound is a voice we need to listen to or background noise we should ignore. Most people don't even realize they possess these skills, much less how adept they are at them. Auditory processing skills play a role in a child's language acquisition and learning abilities, although the extent of that relationship is not well understood.

To determine if auditory processing skills are hereditary, NIDCD researchers studied identical and fraternal twins who attended a national twins festival in Twinsburg, OH, during the years 2002 through 2005. A total of 194 same-sex pairs of twins participated in the study (138 identical pairs and 56 fraternal pairs), representing ages 12 through 50. All twins received a DNA test to confirm whether they were identical or fraternal and a hearing test to make sure they had normal hearing.

If a trait is purely genetic, identical twins, who share the same DNA, will be alike nearly 100 percent of the time, while fraternal twins, who share roughly half of their DNA, will be less similar. Conversely, if a trait is primarily due to a person's environment, both identical and fraternal twins should have roughly the same degree of similarity, since most twins grow up in the same household.

The volunteers took five tests that are frequently used to identify auditory processing difficulties in children and adults. In three of the tests, volunteers listened as two different one-syllable words or nonsense syllables (short word fragments such as ba, da, and ka) were played into their right and left ears simultaneously, and then tried to name both words or syllables. In two other tests, volunteers listened to digitally altered one-syllable words played into the right ear and tried to identify the word. One test artificially filtered out high-pitched sounds, which tended to obscure the consonants, while the other sped up the word.

In all but the filtered-words test, researchers found a significantly higher correlation among identical twins than fraternal twins, indicating that differences in performance for those activities had a strong genetic component. Participants showed the widest range of abilities on those tests in which they were asked to identify competing words or nonsense syllables entering each ear--called dichotic listening ability. The tests in which different one-syllable words were played simultaneously into each ear showed the widest degree of variation as well as the highest correlation among twins, especially identical twins. As much as 73 percent of the variation in dichotic listening ability was due to genetic differences, a magnitude that is comparable to well-known inherited traits such as type 1 diabetes and height. Conversely, the ability to understand the filtered words showed high correlation among all twins, indicating that variation in that skill is primarily due to differences in environment.

Scientists believe that problems with dichotic listening ability are often due to a lesion or disconnect between the brain's right and left hemispheres. When we listen to someone talking, speech entering the right ear travels in large part to the left side of the brain, where language is processed. Speech entering the left ear travels first to the right side of the brain before crossing to the brain's language center on the left side by way of the corpus callosum, a pathway connecting the brain's right and left hemispheres.

Today's finding that normal twins show such wide variation in their dichotic listening abilities, and that the differences are mostly due to genetic variation, adds a new perspective to our understanding of auditory processing disorders. These disorders may affect as many as seven percent of school-aged children in the United States and often appear alongside language and learning disorders, including dyslexia. APDs also affect older adults and stroke victims and can limit the successfulness of hearing aids in the treatment of hearing loss. The researchers suggest that scientists may be able to fine-tune their understanding of what an APD is and the role these disorders play in the development of language and learning disorders.


Story Source:

The above story is based on materials provided by NIH/National Institute on Deafness and Other Communication Disorders. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute on Deafness and Other Communication Disorders. "Ability To Listen To Two Things At Once Is Largely Inherited, Says Twin Study." ScienceDaily. ScienceDaily, 17 July 2007. <www.sciencedaily.com/releases/2007/07/070717014327.htm>.
NIH/National Institute on Deafness and Other Communication Disorders. (2007, July 17). Ability To Listen To Two Things At Once Is Largely Inherited, Says Twin Study. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2007/07/070717014327.htm
NIH/National Institute on Deafness and Other Communication Disorders. "Ability To Listen To Two Things At Once Is Largely Inherited, Says Twin Study." ScienceDaily. www.sciencedaily.com/releases/2007/07/070717014327.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins