Noise Creates Problems Following a Concussion

By Rick McVicar   

  Brainvolts, a neuroscience laboratory at Northwestern University, is studying student-athletes to investigate the brain’s sound processing difficulties following concussions.   

  According to the lab’s website, researchers are studying various types of auditory processes of the brain, such as perceiving music and the effects of aging, as well as concussions.   

  A slide show on the site displays graphics for understanding what happens after a concussion.   

  “Children with concussions have weaker brain responses to sound,” the slideshow states.    

  Nina Kraus, a Brainvolts researcher, was interviewed by NPR science reporter Jon Hamilton for a story that ran on Nov. 5, 2021, “After a Concussion: The Brain May No Longer Make Sense of Sound.”  

  In the story, Kraus is quoted as saying, “Making sense of sound is one of the hardest jobs that we ask our brain to do.”   

  That is because sound enters the brain through two inner ears. The brain must put together information from two sources to determine the sound’s location, pitch and timing.   

   As many different sounds come into the brain at once, the brain must distinguish different sounds from each other. That is what becomes a problem for people who have suffered concussions, Kraus states. 

  Athletes being studied by Brainvolts are given a “speech-in-noise” test while wearing a skull cap with electrodes to study brain waves. The test has the recording of a sentence intermingled with noise.  

  Researchers have found that athletes have difficulty understanding the sentence following a concussion.  A simple hearing test would not detect problems. Athletes are able to hear a single sound when it is isolated, according to Kraus.  

  The skull cap with electrodes tells the story of what happens within the brain while athletes are trying to decipher a sentence with noise. Researchers have noticed that concussions can keep different areas of the brain from communicating with each other.   

  Brainvolts has studied high school athletes as well as college students.    

    Kraus wrote about a study of adolescents in “Concussions Impair Listening-in-Noise Abilities.” The article was published May, 2018 in Hearing Journal.   

  The study involved two tests. In one, students heard a sentence and noise from the same location. In the other, the sentence and noise came from two different locations.   

  The majority of students who had suffered concussions performed poorly on both tests, Kraus writes.  

  Please feel free to comment or share. If you would like to submit material for publication, then contact Rick McVicar through the Contact page.