NPR by Jon Hamilton, 11/5/2021
Headaches, nausea, dizziness, and confusion are among the most common symptoms of a concussion. But researchers say a blow to the head can also make it hard to understand speech in a noisy room.
“Making sense of sound is one of the hardest jobs that we ask our brains to do,” says Nina Kraus, a professor of neurobiology at Northwestern University. “So you can imagine that a concussion, getting hit in the head, really does disrupt sound processing.”
About 15% to 20% of concussions cause persistent sound-processing difficulties, Kraus says, which suggests that hundreds of thousands of people are affected each year in the U.S. The problem is even more common in the military, where many of the troops who saw combat in Iraq and Afghanistan sustained concussions from roadside bombs.