IQ Linked to How Well You Hear in a Crowd

A study of individuals with normal hearing shows that cognitive ability plays a crucial role in successful speech perception.

You’re sitting in a busy café, trying to chat with a friend. The background noise makes it tough to follow what they’re saying. It might seem like a hearing aid would fix the problem, but new research indicates that difficulty understanding speech in noisy places may also be linked to cognitive ability.

Researchers examined three groups: people with autism, people with fetal alcohol syndrome, and a neurotypical control group. Everyone had typical hearing. The team found a significant connection between cognitive ability and how well participants processed speech amid competing sounds.

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

The findings were published today in the journal PLOS One.

Importance and Scope of Findings

Lau emphasized that the study was relatively small, involving fewer than 50 participants, and should be confirmed with larger groups before drawing broad conclusions. Still, she noted that the results highlight how intellectual ability is one of the factors that affects a person’s capacity to follow conversations in challenging sound environments, such as busy classrooms or social gatherings.

To test their hypothesis, the researchers designed a study that included people with autism and fetal alcohol syndrome. People with those conditions, despite having typical hearing, frequently report difficulty listening in noisy environments. And groups of people with those “neurodivergent” conditions represented a wider range of IQ scores — some of them higher, Lau emphasized — than would be seen among neurotypical participants alone. 

The study participants were 12 people with autism, 10 with fetal alcohol syndrome, and 27 age- and biological sex-matched people in a control group. They ranged in age from 13 to 47 years. 

All participants first underwent an audiology screening to confirm clinically normal hearing. They were then equipped with headphones and a computer program that posed a complex listening challenge.  

Participants were introduced to a primary speaker’s voice and instructed to attend to that speaker’s voice as two other “background” voices emerged, all speaking simultaneously. The primary speaker’s voice was always male, and the secondary voices were male and female or both male. Each voice stated a single sentence that began with a call sign followed by a color and number, for example: “Ready, Eagle, go to green five now.”  

On the computer program, study participants were tasked to select a colored, numbered box that corresponded to the primary speaker’s statement, while the volume of the secondary voices gradually increased.  

Testing Cognitive Ability

Subsequently, participants underwent brief, standardized tests of intelligence, including verbal and nonverbal ability, and perceptual reasoning. Those scores were analyzed against individuals’ scores on the “multitalker” listening challenge.   

“We found a highly significant relationship between directly assessed intellectual ability and multitalker speech perception,” the researchers reported. “Intellectual ability was significantly correlated with speech perception thresholds in all three groups.” 

A lot of brain processing contributes to successful listening in complex environments, Lau said.  

“You have to segregate the streams of speech. You have to figure out and selectively attend to the person that you’re interested in, and part of that is suppressing the competing noise characteristics. Then you have to comprehend from a linguistic standpoint, coding each phoneme, discerning syllables and words. There are semantic and social skills, too — we’re smiling, we’re nodding. All these factors increase the cognitive load of communicating when it is noisy.” 

The study directly addresses a common misconception, Lau added, that any person who has trouble listening is suffering from peripheral hearing loss.  

“You don’t have to have a hearing loss to have a hard time listening in a restaurant or any other challenging real-world situation,” she said. 

The authors suggested that neurodivergent individuals and individuals with lower cognitive ability could benefit from an assessment of the environments that may challenge their complex listening thresholds. This could lead to helpful classroom interventions, for instance, such as moving a child to the front row or providing hearing-assistive technology. 

Reference: “The relationship between intellectual ability and auditory multitalker speech perception in neurodivergent individuals” 24 September 2025, PLOS One. 

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