Measuring Hearing Aid Benefits for the Brain

The ICT has been buzzing with activity in recent months, marked by a series of studies and events. One notable endeavor at the Mississauga office was led by Dr. Jonathan Vaisberg, focusing on the investigation of listening effort and its repercussions on hearing aid users. The study has recently concluded leading to valuable insights for the field and for us. Please see below! 

Listening effort, a increasingly crucial metric in assessing hearing ability, has gained prominence in the hearing aid industry. Listening effort is defined as the allocation of mental resources required in carrying out a listening task. Unlike established hearing measurement methods (such as indicating when you hear a tone or repeating a sentence), there is a lack of consensus on the optimal direct method to measure listening effort. While indirect measures have highlighted the adverse effects of heightened chronic listening effort, a standardized direct approach remains elusive. 

This year at the Sonova Innovation Centre, we investigated whether the brain is sensitive to changes in listening effort using a relatively new brain-imaging method called functional near infrared spectroscopy, or fNIRS. With this new method, we are basically able to look at blood oxygenation in the brain! In general, an increased blood oxygenation in the brain is viewed as an increase in listening effort.  We hypothesized that more challenging listening conditions would necessitate increased effort, leading to greater brain activation.

In a controlled laboratory setting, adult hearing aid users were instructed to repeat words in varying noise levels, both with and without hearing aids. As expected, the participants were able repeat more words correctly and stated that used less effort when there was less noise or when they had hearing aids on. We also found that there was more activation in the brain when there was more noise and when participants weren’t wearing hearing aids. These findings suggest that the brain expends more resources in challenging listening environments, offering physiological insight into the fatigue associated with listening without hearing aids. Despite these promising results, further research is essential for a comprehensive understanding of the topic.

None of these advancements would be possible without the continued dedication of our participants, who willingly travel to our locations for various tests. As we look ahead to a promising lineup of studies in 2024, we are eager to share our ongoing progress with you. Wishing you Happy Holidays and a joyful New Year!