Can you listen to a phone message in one ear while a friend talks into the other? If you can, it may be thanks to your genes, scientists report.
Your brain analyzes the sounds you hear so you can make sense of them. This “auditory processing” helps you decide whether a sound is a voice you should listen to or background noise you can safely ignore. Abnormal auditory processing affects up to 7% of school-age children in the U.S. The disorders also affect older adults and stroke victims.
To see if auditory-processing skills can be inherited, NIH researchers studied nearly 200 pairs of twins, ages 12-50. The pairs included both identical twins, who share all of their genes, and fraternal twins, who share about half of their genes. If auditory processing is purely genetic, identical twins will be alike nearly 100% of the time, but fraternal twins won’t.
The twins took several tests that assess auditory-processing skills. For example, they were asked to name 2 different short words or word fragments that were played at the same time, one to the right ear and one to the left.
The results showed that this dual-listening ability is largely inherited. Up to 73% of the variation in this type of listening was due to differences in genes, the researchers say.
These findings will help researchers better understand how the brain processes sound. They may also help to uncover new clues to the causes of auditory-processing disorders.