I love QI. All those facts, half of which will, at some point, be proven to be untrue. I remember that they once asked “if a tree falls in the woods and there is nobody there to hear it, does it make a noise?

There’s another thing that I love, noise. I think that we under value our hearing. Which would you value most, your hearing or your sight? I think that many would value their sight more. Our most expedient means of communication is oral; we hear it, not see it. If someone is talking to you from behind or if the monster from under the bed is sneaking up on you, you may hear it but you wouldn’t see it (unless you heard it first). How much fun is it to watch your favourite rock band with the sound turned off? How about your favourite movie? At least half of the information delivered to us is off screen. We wouldn’t hear those warnings either, such as a car’s horn or a window breaking. Not only that, but our hearing even tells us where the threat is coming from. It’s brilliant! We get so much information from what we hear; perhaps we should value it more.

Whenever anything interacts with anything else, whether that is a tree with the ground or a pin with a desktop, it produces pressure waves in the air. We measure these pressure waves on the Pascal scale. When our ears receive these pressure waves they translate them into noise, which is measured in Decibels, which are in a logarithmic scale, in which an increase of 3dB represents a doubling of noise.

What should we do about noise at work then? The answer is simple, provide hearing protection, right? Well, unfortunately, that is the first port of call for many organisations where there is a noise problem. There are several versions of the hierarchy of risk control and Personal Protective Equipment (PPE) is at, or close, to the bottom of all of them. Hearing protection should be our last ditch effort to prevent harm.

For many, eliminating noise (or some part thereof) is difficult, though that should be our first consideration. If we can’t eliminate the noise entirely, can we reduce the amount of noise that we make? Perhaps we could buy newer machinery. New machines are often quieter than their older counterparts. Maybe simply maintaining what we have to a greater extent could improve things. Securing those service panels or tightening component parts down so that they don’t rattle may help, as may replacing worm parts.

If we can’t reduce the amount of noise to a safe level we must try to prevent people from being exposed to it. In areas where there are a lot of noise sources acoustic barriers, baffles or even softening surfaces might help. Take a look at telephony centres. If we have one piece of equipment or process that causes a significant portion of our noise, we might consider moving it away from most of our people or enclosing it in a noise booth. Depending on the situation, we might even place the operator in the noise booth instead of the machine.

Sometimes we might find that we have a noisy process, which we have placed in a noise booth, which protects people from it but we still need to send people in there from time to time. This is where our Safe Systems of Work (SSoW) come into play. Most of our noise problems arise due to the time exposure as much as the level of noise. This being the case, if we can’t reduce the level of noise enough, we should consider whether we can reduce the time exposure. Perhaps we could tell people that they are only allowed in this area for 2 hours per day (or other specified safe time). Maybe this could be enabled by training everyone on how to do this job, so that they can rotate to task.

Only now that we have done everything else possible should we consider providing people with hearing defence. Once we get to this point, despite all of our other efforts, we have a whole new can of worms to think about, but that’s for another day. In the meantime, you might consider how useful this information is to you. OK, this little lot doesn’t provide the solution for everyone, but it’s a start. We discuss noise, along with 21 other common hazards, during our IOSH Managing Safely training. If this information was useful to you then there might be a bunch of other points covered that might be useful to you too. Why don’t you come along and find out?

Oh yes, the QI question. I nearly forgot. It’s semantics really. If a tree falls it does what trees do when they fall, whether there’s anyone there to hear it or not. Although one could argue that it takes the hearing mechanism to translate those pressure waves into noise. You decide.