Industrial noise levels frequently surpass 85 decibels, which is roughly equivalent to the noise a blender produces. Extended exposure to such noise levels can lead to long-term hearing damage, and earplugs are a common tool to mitigate this risk. However, conventional auditory assessments fail to comprehensively measure the effectiveness and comfort of earplugs in work environments, despite their critical role in protecting against hearing loss.
To address these concerns, recent studies have started using new methods that combine measurable performance tests with comfort surveys.
Olivier Valentin, a research associate in Neuroengineering at the Research Institute of the McGill University Health Centre, is dedicated to learning how we can enhance quality of life for people with hearing disorders and acquired hearing losses. An important aspect of his research pertains to the study of both earplug comfort and efficiency.
“Personal health experiences can also drive research interest, and this is significant for understanding motivations in scientific explorations,” Valentin said in an interview with The Tribune.
Valentin’s curiosity about this field of research was piqued when he was diagnosed with mild bilateral high frequency hearing loss while participating in an auditory research study. He conducted a recent study evaluating the comfort and effectiveness of different earplug types—roll-down foam, pre-molded foam, and push-to-fit—in virtual sound environments. Participants completed tasks designed to assess how well they could hear alarms and human speech, as well as answering questions about their comfort levels.
“There has been a lot of effort in trying to do research for a more accurate simulation, but conventional laboratory studies of multidimensional aspects of comfort in noisy conditions don’t mimic real-life conditions,” Valentin said.
As Valentin noted, the study assessed how different acoustic environments and types of earplugs affect comfort across multiple dimensions. Objective tests—alarm detection and speech perception—and questionnaires assessed the earplugs along the dimension of acoustic comfort, while additional surveys evaluated them along the dimensions of physical, functional, and psychological comfort.
The study found that virtual sound environments mimicking industrial sound exposure significantly impacted how well earplugs work, especially for tasks like detecting alarms and understanding speech. Objective tests showed clear differences in earplug effectiveness across environments, emphasizing the need to fully account for how sound settings affect earplug performance.
Different types of earplugs affected comfort in distinct ways. Participants noted that push-to-fit and pre-molded earplugs caused less annoyance from internal sounds compared to roll-down foam. Roll-down foam and push-to-fit earplugs, on the other hand, led to less physical discomfort and pain than pre-molded ones.
Participants reported physical comfort as the most important factor in evaluating earplugs, followed by functionality and overall comfort. While earplug type had minimal effect on alarm detection, it did impact users’ ability to understand speech in noisy settings.
While objective measures like acoustic performance matter, Valentin warned against overlooking comfort as a factor in protecting against hearing loss, as people are more likely to consistently wear earplugs that are more comfortable.
“Any earplugs and noise-cancelling devices should not only cater to their ability to protect the ear but also to maximize comfort so that we can prevent people from losing their sense of hearing,” Valentin commented.
Although this research focuses on workers in industrial settings, Valentin emphasized that earplugs and hearing loss are relevant to everyone, not only people who are in constant exposure to sound.
“Educating the public about these kinds of misconceptions about hearing loss is critical for promoting hearing safety and preventative measures. That’s ultimately my goal, [which is] to help mitigate hearing losses as they are a growing problem and work with industries that do this work,” Valentin said.
