Your IQ may determine how well you hear in a crowd

Cognitive and auditory ability in noisy environments

Researchers who studied three groups of people — individuals with autism, those with fetal alcohol syndrome, and a “neurological” control group — found that cognitive ability strongly influenced how well participants understood speech in noisy conditions. All participants had normal hearing, but their performance varied based on their intellectual abilities.

“The relationship between cognitive ability and speech perception performance transcended diagnostic categories. This finding was consistent across all three groups,” said Bonnie Lau, the study’s lead researcher. She is a research assistant professor of otolaryngology-head and neck surgery at the University of Washington School of Medicine and directs laboratory studies of auditory brain development.

The results were published in One plus.

Intelligence as a factor in real-world listening

Lau noted that the study’s small sample — fewer than 50 participants — means the findings need to be replicated with larger groups. However, she said the findings suggest that intellectual ability is one of several factors that influence how effectively people listen in complex acoustic environments, such as crowded classrooms or social gatherings.

To test their hypothesis, the researchers recruited people with autism and fetal alcohol syndrome, both groups of which are known to have challenges listening in noisy environments despite normal hearing. Including these neurotypical participants also presented a wider range of IQ scores, with some scoring above average, allowing for a more comprehensive comparison than studying neurotypical individuals alone.

The study included 12 participants with autism, 10 with fetal alcohol syndrome, and 27 neurotypical individuals matched for age and biological sex. – Ages from 13 to 47 years.

Each participant first completed a hearing screening to confirm normal hearing, and then participated in a computer-based listening task.

Multi-speaker challenge.

During the task, participants listened to the voice of the main speaker while two other voices spoke simultaneously in the background. The goal was to focus on the main speaker, who was always male, while ignoring distractions. Each voice issued a short command that included a call sign, color, and number, such as “Ready, Eagle, go to green five now.”

Next, participants selected the colored and numbered box that matched the main speaker’s statement as the background sounds gradually increased.

Next, they completed standardized intelligence tests that measure verbal and nonverbal ability as well as perceptual reasoning. The researchers compared these results with performance on a multiple-speaker listening test.

The results showed a clear relationship between intelligence and listening skill.

“We found a highly significant relationship between directly assessed intellectual ability and multi-talker speech perception,” the researchers reported. “Intellectual ability was significantly related to speech perception thresholds in all three groups.”

Lau said that a lot of brain processing contributes to successful listening in complex environments.

Hearing loss versus cognitive processing

“You have to separate streams of speech. You have to selectively detect the person you’re interested in, and part of that is suppressing competing noise properties. Then you have to understand from a linguistic point of view, encoding each sound, distinguishing syllables and words. There are semantic and social skills too – we smile, we nod. All of these factors increase the cognitive load of communication when it’s so noisy.”

Lau added that the study directly addresses a common misconception, which is that anyone who has difficulty hearing has peripheral hearing loss.

“You don’t have to have hearing loss to have difficulty hearing in a restaurant or other difficult real-world situation,” she said.

The researchers suggested that people who have neurological differences or have lower cognitive ability may benefit from evaluating and modifying their listening environments. In classrooms, for example, simple adjustments such as positioning the student near the front or providing hearing aids can make communication easier.

Lau conducts her work at the University of Wisconsin-Virginia Merrill Bloedel Hearing Research Center. Co-authors represent the Autism Center at the University of Wisconsin, the Institute for Learning and Brain Sciences, and the Departments of Bioengineering, Epidemiology, Pediatrics, Radiology, and Speech and Hearing Sciences at the University of Washington, along with the Department of Otolaryngology-Head and Neck Surgery at the University of Michigan, Ann Arbor.