Exposure to Loud Noise During a Work Shift Can Harm Your Hearing

In many blockbuster movies, you might be familiar with a scene in which a loud blast, car crash, or explosion occurs. From the point of view of the main character, the sound goes suddenly quiet with a high ringing frequency that dominates the soundtrack. Those who experience these situations in real life report something quite similar. In the best cases, their hearing ability comes back, and the sound of ringing goes away. Yet, for some people, exposure to a loud blast is enough to cause permanent hearing loss. 

Despite this popular media narrative, hearing loss does not only occur from exposure to a very loud sound for a very brief time. Another form of noise exposure can cause permanent damage. Those who are exposed to moderately loud noise for long periods of time also experience hearing loss, and shift work is a common cause of this type of exposure. Let’s take a look at the causes of noise-induced hearing loss in the workplace, as well as the relationship with shift work. Some work configurations protect hearing better than others, and you can use this knowledge to encourage your employer to pursue rotating tasks within shifts to minimize your risk of hearing damage. 

Volume and Duration

Noise-induced hearing loss occurs through a combination of volume and duration of loud sound. You can even correlate that volume level in decibels with the time of exposure in hours or minutes. Most people can be exposed to 85 decibels of noise for a full 8-hour shift without permanent hearing damage. With each additional 3 decibels of sound, however, that duration is cut in half. For instance, a person can endure 88 decibels of sound for 4 hours without incurring hearing damage. As you might predict, this equation leads to very rapid durations of time at higher decibel levels of volume, and the example of a single blast, crash, or explosion explains just how quickly extremely loud sound can cause hearing loss.

Workplace Exposure

When it comes to workplace noise exposure, these durations are crucial to understand. If the decibel level of your workplace remains at 85 decibels and below, then you might not need hearing protection for your shift. However, those who have louder workplaces cannot endure a full working shift at the same location without risking hearing loss. Hearing protection is labeled with the decibel level of protection it provides. Most basic, disposable, foam earplugs provide at least 10-15 decibels of protection, meaning they can, in effect, reduce the duration of exposure that your employer can allow. For very loud workplaces, such as air strips or factories, noise-cancelling earmuffs or even more advanced protection may be necessary. 

Noise Exposure and Shift Work

A recent study demonstrated that shift workers are especially prone to hearing damage. Particularly when they are exposed to loud sound for the entirety of their shifts, earplugs might not be enough to protect their hearing. In these cases, the most effective strategy is a rotating task-oriented shift through the day. Rather than working 8 or more hours at the same noisy station, workers can benefit from limiting their time at one task before moving to another task in a quieter location. In order to plan and arrange this type of scheduling, accurate decibel readings at the various workstations is necessary. Not only is a single reading enough to capture a precise measurement. Several decibel readings from the working station should be taken to get a true picture of the maximum amount of exposure that will occur. Each working station has its own sonic profile, and that measurement should be used to determine how long a worker can stay in place. 

If you work in a loud environment, talk to your employer and union representatives about the appropriate protection measures. It doesn’t hurt to take your own decibel readings at work, and free smartphone apps are available to perform this measurement. Once you have a sense of how loud your workplace is, you will have a better sense both of how long you can work in a single task, as well as the level of protection you will need to make it possible to work an entire shift without risking damage to your hearing.