Humans still have ear muscles that helped their ancestors focus on sounds, and research shows these muscles activate when we strain to hear in noisy environments. Scientists used electromyography to measure the activity of these muscles in people listening to an audiobook with distracting background noise. The superior auricular muscle responded most when participants struggled to follow speech, suggesting it could be used as a measure of listening effort.
A study published in Frontiers found that millions of years ago, humans’ ear muscles were more active due to their ability to localize sounds. However, over time, these muscles became vestigial and lost their function. Recently, researchers discovered that these muscles still activate when we’re trying to listen to competing sounds, even though they don’t seem to improve our hearing.
The study involved 20 participants who listened to an audiobook with distracting podcasts in different conditions. The scientists found that the posterior auricular muscle reacted to changes in direction, while the superior auricular muscle responded more to difficulty levels. The results suggest that the activity of these muscles could provide an objective measure of listening effort, which could be useful for individuals with hearing impairments.
The researchers pointed out that further work is needed to confirm these findings and develop practical applications. They also noted that the sample size was small, and more diverse participant groups are necessary for larger-scale studies. Despite this limitation, the study provides valuable insights into the role of ear muscles in human hearing and could lead to new methods for assessing listening effort.
Source: https://neurosciencenews.com/ear-muscle-hearing-28399