Hearing aid manufacturer Oticon has applied “pupillometry” science—a measurement of pupil dilation— to develop hearing aid technology that both reduces listening effort and conserves energy so that people recall more of what they’ve heard.
In a just-released study, researchers at Eriksholm Research Centre and the VU University Medical Center set out to answer key questions, such as how hard a brain has to work to understand speech in different environments and how that knowledge could be leveraged for use in new hearing devices. Their findings reinforce much of what is known about the impact of hearing loss and listening effort on cognition.
“When we pay attention to sound, the muscles in the eyes contract and release based on listening effort,” said Thomas Behrens, Head of Audiology and Director for the Centre for Applied Audiology Research at Oticon’s global headquarters in Denmark. “In our research, we showed how pupillometry could be used to measure strain on the brain’s processing power when trying to understand speech.”
According to Behrens, the more challenging the task, the larger the pupil. In looking into the eyes of Opn wearers as compared to Alta2 Pro hearing aids, the researchers saw 20 percent less listening effort when trying to understand speech while others are speaking. Additionally, they saw an average reduction in peak pupil dilation of 26 percent during the speech-noise reduction task using Opn compared to Alta2 Pro.
“The results for measuring peak pupil dilation were statistically significant (p=0.04), indicating a significant reduction in peak pupil dilation,” Behrens said. “These data demonstrate that Oticon’s Opn is the first hearing aid proven to make it easier for the brain, freeing up the cognitive resources for more recall.”
