Noise Induced Hearing Loss

We live in a world that is getting louder and it could be damaging your hearing. We are surrounded by noise at work, through personal entertainment devices (your own and other people’s), on the commute, at bars, restaurants and concerts. So just how loud is too loud for the health of your hearing?

Research indicates that hazardous noise levels in the workplace are a problem for at least 30 million people in America each year and that 25% of those people will develop permanent hearing loss as a result. And the situation in Canada is no different.

And noise levels can hurt your hearing even when you’re having fun. Many restaurants, bars, and even shops use loud music to create atmosphere and increase customer spend and turnover. Add in the background noise of plates and cutlery clashing and large groups of people talking and the noise levels can quickly become dangerous.

You might be surprised to learn that the average sound level in Toronto nightclubs hits 96dB—that’s dangerously loud. So how loud is too loud? Well, volume is only part of the problem. The length of exposure also has a big impact on how well your ears can cope with noise.

How do we measure noise?

First, knowing how sound is measured will help you to work out how loud is too loud. Decibels are the commonly used measurement of sound intensity. The decibel rating from 0 up to 140 and beyond represents sound intensity as the average human ear perceives it. 

The decibel scale is an algorithmic scale. This means that a 3 dB increase is actually the equivalent of twice the sound intensity. To put it into real world terms; the sound of a machine running at 80dB is actually 100 times more intense than one at 60dB.

To make it more complicated, this intensity or power does not directly correlate with our perception of loudness. And because our perceptions can vary according to human differences and are very subjective, perceptions of loudness are not very useful for measuring risk to hearing.

For example, imagine a party blasting music next door while you’re trying to sleep; you might perceive the music as unbearably loud but the partygoers have a different view. That’s why researchers consider sound intensity to be a better indicator of hearing risks.

Any workplace that has concerns about noise levels will use a noise dosimeter to measure sound levels. And if you’re serious about monitoring sound levels in your workplace, you can also download an app from the National Institute for Occupational Safety and Health (NIOSH). It allows you measure noise levels for yourself and it’s accurate to within 2dBs.

Keep in mind that a number of factors will affect the noise level reading including:

  • How far the sound source is from the meter 
  • Whether the noise source is facing the meter or not
  • Environment acoustics –outdoors (allows noise to dissipate) or indoors (increased reverberation)

Whether a sound is too loud or not usually depends on a mixture of decibel level, how close you are to the sound, and the length of time you’re exposed to it.

Volume and exposure

Government regulations control the amount of noise exposure in the workplace. Most parts of Canada and the USA recommend a maximum exposure time of 8 hours without hearing protection to continuous noise levels of 85dB. Your exposure time for every 3dB noise level increase above this should be halved.

To give you an idea of just what 85dB sounds like, it’s the equivalent of busy city traffic or a freight train 100 feet away. Exposure to sounds at this level for more than 8 hours will cause permanent hearing loss over time.

What is a safe noise level? Researchers consider noise levels of 70dB or lower to carry no risk of hearing loss regardless of how long you listen to them. Typical conversation or a quiet washing machine would produce around 70dBs. Whereas, a personal entertainment device can easily reach 100dB and hearing loss at this intensity can occur after 30 minutes of listening. 

But another part of the problem is that noise exposure is cumulative. So, if you experience the maximum recommended noise levels at work but then put ear buds in your ears and listen to music on the commute home, you will cross that safe exposure limit. 

The other problem with these safe exposure guidelines is that they are suitable for the average human. Respecting these limits does not guarantee that you will not suffer hearing loss.

In fact, the National Institute for Occupational Safety and Health (NIOSH) admits that some 8% of workers could still develop hearing loss even while adhering to these recommended levels.  Most hearing experts recommend that you wear hearing protection whenever noise levels exceed 85 dB(A) regardless of the length of exposure.

Is there an easy way to tell if it’s too loud?    

Here are some simple guidelines you can use to work out whether the noise around you is too loud.

You need to protect your ears and limit your exposure if the noise means you:

  • Shout to be heard by someone next to you
  • Find it difficult to understand the conversation
  • Frequently ask the other person to repeat themselves 
  • Experience ringing in your ears at the end of the day

Protect your ears against noise

If you work in a noisy environment then you need to protect your hearing. Hearing protection such as earplugs or earmuffs is a good beginning. Check out our wide range of custom shaped earplugs. These are specially designed for a variety of occupations and leisure activities.

Restrict the amount of time you expose yourself to loud noise. That means if you have to work with those noise levels make sure you give your ears a rest by maintaining a quiet environment outside of your work hours. It’s also important to try to maximise your distance from any loud noise source. This is because sound intensity quickly drops over a relatively short distance.

Ignoring the risks of damaging sounds can have a lasting impact on your life. Take a step towards protecting your hearing and visit House of Hearing for truly sound advice on how you can look after your ears.