Stereo noise in the workplace
Can stereos be used and how loud should they be?
Following a noise assessment in their factory, a client has decided to install a distributed music system to given an even sound throughout the factory and asked an interesting question - how loud should a stereo be at work? Good question indeed.
It is not entirely uncommon on a noise assessment to find a situation where the loudest thing in the room is a car-boot-special stereo blasting away. The ones with four feet tall speakers and lots of glowing lights bought out of the back of an old Astra parked in a field somewhere. Mostly it is adding significant background noise but sometimes the noise assessment shows the noise is to the extent that if they turn the stereo off then hearing protection is not needed, while with it on they are over the noise limits and hearing protection and even hearing testing are now mandatory.
Real-world stereo noise impact on a noise assessment
As a real world example - on a noise assessment I was measuring a spot welding area with a stereo on and levels were averaging 88 dB(A). I turned the stereo off and immediately the average levels dropped to 79 dB(A) as spot welding is not a loud process. That stereo was the difference between hearing protection and hearing testing being needed rather than being not necessary.
What do the Noise Regs say about stereos?
The Noise Regs talk about volumes (I know Noise Nerds, it is technically sound pressure level, but this is aimed at real people rather than those of us who have a favourite decibel weighting scale) and don’t really talk about specific noise sources, but we can still glean some information.
General duty to reduce noise levels
There is a requirement for employers to reduce noise levels.
The first of these in (1) means that an employer must reduce noise levels generally, even if the limits of 80 or 85 dB(A) are not being reached and the noise level in the factory is 79 dB(A) or lower. The fact of being below the limits doesn’t remove the obligation to reduce noise in the workplace.
However, the accompanying guidance is clear on how much an employer has to do here:
So, where levels are below the lower 80 dB(A) limit, item (1) does mean the employer still needs to look at reducing noise levels further if they can but then item 63 in the guidance above stresses ‘inexpensive’ or ‘simple’ measures.
If noise levels exceed the 85 dB(A) point then the strength of that ‘get the noise back down where you can’ element in (2) above comes into play and more is expected to be done.
Where do factory stereos fit into this?
This plays a part as that general duty to minimise noise levels still applies, even if your factory noise is below 80 dB(A).
That means adding in a stereo noise is technically going directly against what you are supposed to be doing - minimising the noise where you can.
Real world vs ideal world
With the best of intentions, the HSE do sometimes inhabit a parallel universe where things are perfect and safety is the One True God but the real world is not so simple. If some dude is standing watching a plastic extruding machine for eight hours a day his brain will slowly scream for release and having something to listen to can make a big difference to people’s days.
I would absolutely say that stereos have a function at work and that this function is important - it is not trivial or an unnecessary noise. I have seen HSE letters to employers describing it as such but that is incorrect - there is a value in it for a lot of people.
It is all very well people in the HSE saying to eliminate noise wherever possible, even if below 80 dB(A), but they have nice interesting jobs where they get to float around different places every day, seeing different things, and are not standing watching the same carpet threading machine non-stop for 40 hours a week, every week, every month. This is why I use ISOTunes Air Defenders on a lot of noise assessments - when you are standing waiting for wearable dosimeters to do their thing there is only so long you can watch new rivets coming out of a machine before sticking your hand into the press becomes a vaguely interesting possibility just to relieve the boredom. Having something to listen to helps and has definite value in a workplace and the general ‘reduce noise levels where you can even if below the limits’ seems a bit too simplistic and idealistic.
Put it this way, that same duty to reduce noise levels where possible applies to all workplaces and all noise. I bet the HSE Inspectors driving to sites still have the stereo on in their car even though they are ‘at work’ and that general duty to minimise noise still applies. I would bet the mortgage the HSE haven’t banned their staff from listening to their car stereos in order to reduce noise exposure levels, even though noise levels in a car are commonly easily over the 80 dB(A) point. Common sense clearly has a part to play.
Stereos need to be heard
The noise safety issue arises as to be heard, a factory stereo has to be the same volume or then the general noise in the factory, otherwise it is fairly pointless.
In reality, stereos which are the same volume as the general noise are still pretty useless as there will be no clarity, nobody will be able to make out much of what is being said or sung, and unless you are directly by a speaker you probably won’t hear it at all. In these cases the stereo is just adding to the general mush of noise.
Generally, stereos need to be louder than the background noise, and given a choice, most people will make it significantly louder as they want to hear the music, not an orbital sander. This can make the stereo into quite a significant noise risk.
Where the noise assessment shows levels over 85 dB(A) or 137 dB(C)
Where the noise assessment has shown that noise exposures are meeting or exceeding the upper limits then I’m afraid it is pretty simple, no stereo.
In order to be hear it will need to be at least 85 dB(A) and probably a lot louder, and now item (2) in the Noise Regs above kicks in saying the employer needs to get levels back below the limit. So if your noise exposures are 85 dB(A) or above, no stereo.
The noise assessment shows levels of 80 to 84 dB(A) or 135 dB(C)
Of the three cases here, this middle one is the most uncertain to be honest. I am reluctant to say yes, go ahead and stick a stereo in there on the basis that to be heard, especially over a wide(ish) area it is going to need to be louder than the background noise, which in this instance is already over the lower 80 dB(A) limit.
That means chances are the stereo is going to louder still and therefore getting very close to that magic 85 dB(A) limit, or even over it.
Personally I would be reluctant to put a stereo in an area with this kind of general background noise level, it seems an unwise risk.
Where the noise assessment shows levels of 79 dB(A) or below
Here, the noise assessment has shown an absence of risk so as long as your stereo isn’t so loud it then pushes the overall averages up again then go for it.
Yes, that general requirement to reduce noise levels in a factory still applies, but so does staff well-being and stereos can help in staving off boredom levels which can become near-fatal. A happy, or at least happier, workforce is not trivial and if some music helps with that then so be it.
For quiet areas like stores, offices, etc. then as long as it is not banging away excessively loudly, go for it.
How loud should your stereo be?
Firstly, I would always recommend a proper distributed system rather than nipping down to the local car boot for some ten quid 1990s 20-band graphic equalising monster, or a load of bluetooth speakers. With those people always blast the noise out to try and cover a wide area meaning some people have very little stereo noise while others spend all day in the equivalent of an Ibiza club.
Another important point - with a distributed system the volume control can be in a manager’s office, so no temptation to keep pushing it up and up on the shop floor. The company can manage it.
I would personally look for a level around 78 dB(A) at the highest point, so by the speaker, although around the low-70s to about 75 dB(A) would be even better and preferable. That will not drown out other important sounds like machine noises (staff often tell everything is running OK by how their machine sounds), alarms, forklifts, etc. It also has a bit of wriggle-room on top between the stereo noise and the main noise limit.
Once in place, I would recommend you check that if anyone is working where vehicles such as FLTs may operate that they can still hear them, and hear things like fire alarms.
An alternative if noise levels generally are over the 85 dB(A) limit
Where the noise is loud and over the limits, people will still often want to listen to something for their own sanity but it is too loud for a stereo system. In these cases I would recommend bluetooth-enabled hearing protection and of them all, you really can’t go wrong with the ISOTunes range. I use the ISOTunes Air Defenders myself a lot.
They are volume-limited meaning they will not play back at dangerous levels unlike ‘normal’ headphones.
They are certified hearing protection, again unlike normal headphones.
They do not isolate staff so they can still hear vehicles, alarms, people speaking, etc.
Where they are used companies often see a huge improvement in compliance with the wearing of hearing protection as people actively want to wear them.
If you use disposable plugs, the per-person cost of the ISOTunes Air Defenders is usually around the equivalent of something like four of five months of disposable plugs use. Basically after five months the employer is quids-in, it is cheaper.
Everyone can listen to their own thing rather than getting whatever is being blasted out, especially when Mad Brian gets hold of the stereo and decides today is going to be death metal day. Or even worse, a dedicated Swiftie gets control of the stereo and everyone has a day of maudlin angst to listen to.
Avoid some of the no-brand or off-brand tat on Amazon - there are a lot of sellers peddling bluetooth-enabled hearing protection. I have tried a lot of them and they are universally dreadful - uncomfortable to wear and poor music playback quality. With ISOTunes you can’t go wrong, but also 3M, Honeywell (Leight) or the other big players also do good ones.
