An X-Ray of a Human brain with parts like the auditory cortex highlighted in several colors.

Scientists discover new information about the auditory cortex and the role it plays in hearing.

According to the National Institute on Deafness and Other Communication Disorders, nearly 10 percent (25 million people) of the United States population has experienced tinnitus lasting at least five minutes. Approximately 15 percent (26 million people) of Americans, between the ages of 20 and 69, have hearing loss due to exposure to loud noises.

Scientists continue to search for answers to how hearing loss affects the body. A recent study has made an interesting discovery about the auditory cortex—which is the part of the brain that processes sound.

Revealing Details About the Auditory Cortex

Researchers at several institutions, including Harvard University, sought to better understand how the auditory cortex works. Using tonotopic maps (images of the brain), the scientists were able to analyze how this part of the brain reacts to different tones. They discovered that for both the hearing impaired and those with normal hearing, the neural architecture in the auditory cortex is identical.

“One reason this is interesting is because we don’t know what causes the brain to organize the way it does,” said Striem-Amit, the lead author of the study. “How important is each person’s experience for their brain development? In audition, a lot is known about (how it works) in hearing people, and in animals…but we don’t know whether the same organization is retained in congenitally deaf people.”

The result of the study raises a lot of questions. In their test, the auditory cortex reacted to not only sound but visual stimulation. “We know the architecture is in place—does it serve a function?” Striem-Amit said. “We know, for example, that the auditory cortex of the deaf is also active when they view sign language and other visual information. The question is: What do these regions do in the deaf? Are they actually processing something similar to what they process in hearing people, only through vision?”

More research needs to be done. While the auditory cortex seems to develop in a similar manner, whether or not the person is deaf, some suggest it still might play a vital role in hearing.