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High Noise Levels Cause Injuries

High noise levels make you shout to be heard? You’re at high risk for on-the-job injury. Hear about noise-induced hearing loss and accidents.

Prof. Tony Leroux of the University of Montréal tells about his group’s recent study on hearing loss and work-related injuries.

This new study says if you already have noise-induced hearing loss, injury risk is substantially greater.

Dan Clark interviews Prof. Leroux who also explains that extreme sound, over 100dBA, is very dangerous. Engineering controls to reduce the sound are the best option, but both OSHA, and their Canadian counterpart, CCOHS, focus on hearing protectors for workers. He would rather see the noise reduced at the source.


Brandon Nys: Welcome to Safety Experts Talk. Visit our website at for more info, including links and transcripts.

Introduction music

factory sounds

Worker 1: Look out! Look out!

Worker 2: What?

Dan Clark: Do you have to shout to be heard by a coworker, even though they’re right next to you?

Prof. Tony Leroux: Hearing is like our RADAR for safety.

Dan: A new study says high noise levels put you at a higher risk for on-the-job injuries.

Prof. Leroux: 356% more injury.

Dan: Hello, I’m Dan Clark. Today we’re talking with Prof. Tony Leroux of the University of Montréal about his group’s recent study on hearing loss related to work-related injuries. Hello professor, how are you?

Prof. Leroux: I’m, I am fine.

Dan: This is pretty amazing. You surveyed 46,000 workers who had exposure to high noise levels at work. What prompted you to do this?

Prof. Leroux: Uhm, we were wondering if workers who have already noise induced hearing loss and, on top of it, are still working in a noisy environment, if those two conditions together were putting workers at risk of injury.

Dan: Okay, and let me see if I can boil this down. Through this enormous survey you found that the higher the hearing loss, the more chance of injury on the job in high-noise environment.

Prof. Leroux: Yeah, that’s right.

Dan: If you can’t hear well, you can’t hear a danger warning well.

Prof. Leroux: If you hear something then you will turn around and see if a danger is coming up. So hearing is like our radar for safety.

Dan: And you really had a spike in Intense levels of sound. That’s over 100 dBA, right?

Prof. Leroux: Yes.

Dan: And, of course, you’re supposed to wear hearing protection for anything over 80-85 dBA, like a lawnmower at 85.

lawnmower sounds

Dan: A circular saw plus hammering, that’s about 95+ dBA.

sawing, hamming sounds

Dan: But an example of Intense sound at over 100 dBA would be a bulldozer with no closed cab.

bulldozer sounds

Prof. Leroux: Yes.

Dan: Tell us about those.

Prof. Leroux: So, at those high levels we’ve seen a very, very large risk of injury. So, it’s like 356% more injury in this group compared to workers working in between 80 to 89 dBA, which is still quite loud.

Dan: Well, this is a big problem. What’s a worker supposed to do? You know, they put on more hearing protection, then they really can’t hear any warning signs.

Prof. Leroux: Yeah, for, for sure. One thing is that hearing protection might—I say might—protect hearing but at those high levels at 100 dBA, you might not be able to detect warning sounds. You might not be able to detect speech because on top of the noise, you also have a hearing protector. At those high levels, there’s a very large risk of injury.

Dan: Is, is anybody talking about reducing the source of the noise? You know, lubricating the machinery, putting up a sound wall, somehow isolating the noise source. Is anybody talking about that?

Prof. Leroux: Ah, honestly no. This is not a big topic. Noise is not visible enough. At least in Québec, we see people in Health and Safety putting a lot of energy in, um, distributing hearing protection without doing anything on the noise itself.

Dan: Mm-hm.

Prof. Leroux: In Europe, there is a larger pressure to go through engineering control of noise sources, mainly because the, ah, cost of any compensation for noise induced hearing loss is a lot larger in Europe compared to what it is, at least here in Québec.

Dan: Ah! Okay, there’s a universal topic. The pocketbook.

Prof. Leroux: (laughs)

Dan: It would benefit companies to make an engineering change to reduce the noise just to cut down on the cost of worker injuries.

Prof. Leroux: Yeah. If you look at our results in a, ah, employer’s point of view, injuries cost a lot more than just noise induced hearing loss.

Dan: Right. Yeah, absolutely.

Prof. Leroux: So, there’s a source for saving there.

Dan: Have, have you, sir, ever worked in a loud work environment besides the classroom?

Prof. Leroux: Oh, yes. I work in a steel forge when I was a student.

Dan: And did you have any hearing loss?

Prof. Leroux: Yes I have. I have a slight noise induced hearing loss.

Dan: Wow. And how long did it take for that to reveal itself to you?

Prof. Leroux: Uhm…I start sensing it more in my late 30s.

Dan: Right.

Prof. Leroux: And the only exposure I had was working at the forge. (laughs)

Dan: Wow, and it took 10 or 15 years before even noticed it.

Prof. Leroux: Yeah, to get worse and also to giving you trouble to understand speech and noise environment at restaurants, or, um, with groups of people.

Dan: It affects your entire life no matter what.

Prof. Leroux: Yes.

Dan: And beyond work there are sound risks too, like if you go to a sporting event. World Cup soccer game and that crazy horn—the vuvuzela.

(vuvuzela sound)

Dan: That’s loud.

Prof. Leroux: Yes, 108 dB.

Dan: 108, that’s the same as an impact wrench.

(impact wrench sounds)

Dan: So, if you’re at soccer stadium and somebody’s next to you, ask to be seated elsewhere.

(vuvuzela sound)

Prof. Leroux: (laughs) And I, I think there’s a, a myth around noise levels or sound levels and it’s, like, associated with a lively environment. But it has some deadly impact on hearing (laughs).

strong>Dan: Well, I think the advice is “take ear plugs everywhere.” Well, thanks very much professor. This discussion has been important. I think, maybe, employers need to do more to engineer the sound reduction in their facilities.

Prof. Leroux: Thank you. Our team is very pleased by that kind of study we are conducting, because one of our objectives is to show that noise induced hearing loss is not the only effect of noise exposure, has some other effect on health and on safety also. And this piece of work was important for us.

Dan: Well, we really appreciate you talking with us. Best of luck on your future research.

Prof. Leroux: Thank you very much.

Dan: Our guest has been Prof. Tony Leroux of the University of Montréal about his research group’s study on hearing loss, noise and workplace injuries. The study can be accessed from, under this podcast. I’m Dan Clark.

(Outro Music with Voiceover)
Brandon: Thank you for joining us on Safety Experts Talk. If you have suggestions for future podcasts, send them to For more safety experts talking about safety news, OSHA regulations, PPE, lean, 5S, or Continuous Improvement, go to


View a PDF of the study here.

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