Circadian Rhythm and Your Hearing

Over the weekend, we marked the end of daylight savings time and the return to standard time by pushing the clocks back an hour. While an hour shift may not seem like it would have much impact, it can still take some time to readjust your sleeping – and even eating – habits.

The reason? Your body’s internal clock produces what’s known as the circadian rhythm, which dictates how sleepy or alert you are throughout the day. This inner mechanism accounts for why you sleep when it’s dark out, wake up with the sunrise, or feel sluggish after eating lunch. And research suggests that significant disruptions to this natural process can negatively affect your health – including your hearing.

Ears are more sensitive at night

The disruption to the circadian rhythm from changing the clocks is usually minor. We get used to the changes after a week or so – until we push the clocks forward an hour in March and have to readjust all over again. However, for those who face more drastic disturbances to their circadian rhythm, like people who work at night, the impacts can be much worse.

A 2014 study explored how excessive noise impacts mice at different times of day. It found that the mice exposed to noise trauma at night were shown to be more affected than the mice who were exposed during the day. In addition, those mice that were exposed to noise during the day recovered fully from the experience, while those exposed at night sustained permanent hearing damage.

A more recent study aimed to see if the same holds true for humans, examining textile workers who perform their jobs either in day shifts or alternate between day and night shifts. The conclusion is that the employees who work both day and night shifts had more pronounced hearing loss than their peers who work only day shifts, further highlighting how your ears are more susceptible to noise damage at night.

Safe hearing at all times

Given the evidence of how disrupting your circadian rhythm can affect your hearing, it raises new concerns for people working in manufacturing, air travel, medical, emergency services, and any other industry in which employees are required to work night shifts. While many of these jobs are essential and require people to work at night, there may need to be greater regulations around the sound levels they’re exposed to on the job.

The changing of the clocks may throw your circadian rhythm off balance for a few days. But if your rhythm is regularly off-kilter due to working night shifts, you may be at increased risk of developing hearing loss. If you think your hearing may already be affected, it’s a good idea to schedule an appointment with a hearing care professional to evaluate your hearing and recommend any necessary treatment.