Earplug & Noise Reduction Ratings Explained

One of the most common ways to lower incoming noise is to use earplugs. They’re a simple yet effective device that can drastically reduce the volume of sounds around you. They are commonly used for situations such as loud work environments or concerts. If you are concerned about hearing loss, then it’s a good idea to purchase a pair of earplugs to help you lower the volume of sound around you when you are in a noisy or busy environment.

To help you choose a good pair, most earplugs are given a noise reduction rating (NRR). In this post, we’ll be explaining what NRR is and how you can use it to determine if a pair of earplugs is a good investment or not.

What Is an NRR Rating?

An NRR rating is a number given to a pair of earplugs or earmuffs that have been tested for their ability to reduce incoming sound. Currently, the highest NRR rating for earplugs is 33, and the highest for earmuffs is 31. These are values for when the ear protection is worn alone. However, if they are worn together, it’s possible to achieve an NRR of up to 36.

NRR ratings are affected by the overall design and build quality of the earplugs or earmuffs. Generally speaking, a more cost-effective product will generally offer a greater protection rating because it has been designed with more research behind it. NRR ratings can also apply to both short-term disposable earplugs and long-term earplugs.

How Do I Use NRR Ratings?

For most people, simply picking a product with a higher NRR rating will result in better ear protection. However, NRR is actually measured in decibels – it’s not an arbitrary number. Unfortunately, it’s not a flat calculation. For instance, if a sound is at 80 decibels (dBs), wearing earplugs rated at NRR 26 doesn’t mean that the sound will be reduced to 54dBs. Instead, there’s a bit of math involved.

The calculation is as follows:

• Take the NRR rating
• Subtract seven from the rating
• Then divide by two
• Subtract this from the source sound

In other words, the sound will be reduced to 73 decibels. This can be significant enough to lower a sound down to a safe level. There are also other factors that may affect the effectiveness of ear plugs. For instance, if earplugs or earmuffs are worn incorrectly, then you might experience a lower sound reduction.

Some calculations omit the division by two. This gives a much higher sound reduction rating, but only applies to optimal conditions. For example, if the hearing protection device is fitted correctly and laboratory conditions are used to measure the sound reduction. This isn’t a realistic measurement of a real-world situation. This is because everyone’s ear canal is different, meaning earplugs don’t always fit perfectly.

As such, sound may leak into your ears as the seal isn’t as tight as the laboratory conditions that the earplugs were tested in. Because of this, it’s recommended to apply a 50% correction factor, hence the division by two. However, it’s perfectly acceptable to consider the hearing reduction with the 50% correction as a worst-case scenario, and the best-case scenario without the correction factor. So, for the above example, you can expect anywhere between six decibels and 13dBs reduction in sound.

In short, a higher NRR rating will result in a greater sound reduction. Using the formula that we have provided; you can roughly measure how much hearing reduction you’d get if you know how loud a sound is.

How Much Noise Is Excessive?

The Occupational Safety and Health Administration (OSHA) recommends that you do not expose yourself to loud noises for too long, otherwise you risk being affected by hearing loss.

At the most severe level, just 15 minutes of exposure to sounds at 115dBs or higher can cause hearing loss. If you are exposed to around 90dBs of sound for around eight hours per day, then you will also experience hearing loss. As you can see, the amount of exposure time that leads to hearing loss can be quite long, but it’s easy to neglect just how loud certain sounds are and how long you’re accidentally exposed to them.

Learn More Today

Interested in learning more about hearing protection solutions? Worried about hearing loss and want a full diagnosis? Don’t hesitate to contact us today at Hearing Solutions of Louisiana, LLC to learn more. Simply call us today at (337) 607-0630 to speak to one of our friendly members of staff or get in touch online by emailing us or sending a message.