The Basics of Noise

We talk a lot about the impacts of noise and advances in noise-controlling technologies and legislations here at NoiseNet. But what actually is noise? How is it defined by the people it affects, and by the people with the power to mitigate it? Let’s take a look at some solid definitions of noise, how and when it can affect people, and what general practices governing bodies put into place to keep it under control.

What is Noise?

Noise is sound, but when we say ‘noise’ we specifically mean ‘nuisance noise’, which is any sound that is unwanted or unpleasant. It is often defined as being harsh, sudden, repetitive, and/or prolonged. It is always loud and unignorable.

Noise is measured in ‘decibels’ (dB), which are a complex mathematical formula used to describe the amount of air pressure a particular noise carries. For reference, a normal conversation in a quiet room is around 60dB, a hair dryer is around 90dB, and a nearby ambulance siren is 120dB. This air pressure is caught by our eardrums, which vibrate to the same rhythm and intensity as the air pressure, letting us perceive the sound source. This air pressure also dissipates with distance, which is why the closer a sound is, the louder it sounds.

Where Does Noise Come From?

For the general public, most noise comes from neighbours, transport, urban development, or entertainment venues. This can be untrained barking dogs, lawn mowers and power tools, nearby train lines or souped-up cars, construction sites, or even the local pub’s open mic night.

In professional and industrial settings, noises are often more intense. Explosions, heavy machinery, moving materials, and communications equipment are commonplace. However, noise protection equipment is also more commonplace, making mitigation requirements different. When these work sites are in urban areas, those sounds are typically loud enough to impact local residents, which is a large consideration in regulations.

Why Does Noise Matter?

We’ve mentioned “impact” quite a bit so far, but what does that mean? Well, there are a few ways that noise can affect our health.

Firstly, if a noise is at or above 130dB it can cause immediate pain, as the air pressure from the sound is more than our eardrums can handle. This causes lasting damage, and can lower our overall hearing abilities, even causing deafness.

Prolonged exposure to noises over 85dB (roughly equivalent to a diesel lawn mower) will have similar impacts on our hearing abilities, but don’t typically inflict immediate pain, making it much harder to recognise when a noise will be damaging.

Secondly, hearing a loud, unwelcome noise activates our brain’s primal fight-or-flight response. This floods our bodies with a burst of adrenaline, and if that adrenaline has no way to be burned off it can cause lasting mental and physical health problems. Generalised anxiety is a primary concern, and can manifest as anger issues, insomnia, and/or paranoia. It can also cause heightened blood pressure (a.k.a. hypertension), which can lead to headaches, shortness of breath, nose bleeds, and, if left untreated, life-threatening heart problems.

Noise is More than a Number.

So often you will hear someone referring to a noise as being so-and-so decibels (just as we have done above). But a decibel number by itself means nothing. To understand the impact of noise on people, we need to know four other things:

1. Where was the measurement taken?

2. Where is the person being affected by the noise?

3. For how long does the noise last/repeat?

4. What are the characteristics of the noise?

Until you have all this information, decibel readings mean nothing. What is most important is the level, the duration and the noise characteristics at the ears of the person affected. All too often, noise assessors only measure from right by the source, and don’t account for duration or repetition. This is the source of much of the conflict around noise management.

Who Does Noise Affect, and When?

Noise impacts everyone, but those who expect to be able to live peacefully within their own homes often feel the mental health effects the most, while insufficiently protected industrial workers experience the bulk of the physical consequences.

Residents in their homes are primarily affected by noise between the hours of 10pm and 7am, when nuisance noise will be interrupting their sleep. These are also the times when governing bodies have the greatest authority to enforce noise complaints, ordering loud music to be lowered, noisy vehicles off the roads, or any other noise source to be ceased.

Workers in any industry where heavy machinery is common will be impacted by noise during working hours. It is the onus of workplace health and safety regulators to ensure those workers are safe through regular equipment maintenance and upgrades, procedure updates, and proper personal protective equipment (PPE) requirements.

Excessive noise also has a tangible effect on local wildlife. Studies are showing that many species which rely on sound for communication, such as birds, frogs, bats, and marsupials, are experiencing population declines as their mating calls aren’t being heard as easily.

How Can We Keep Noise Under Control?

It largely depends on the source of the noise in question. If you’re a resident, your local council will have procedures on their website that you can follow to lodge a complaint. If your complaint is regarding a venue or construction site, government regulators have a good degree of power to reduce excess noise outside of allowed hours.

If your nuisance noise is coming from another resident, such as barking dogs or power tools, the best and quickest way to resolve the issue is to talk to them. Explaining amicably that their noise is affecting your quality of life — and potentially your health — will often lead to a positive outcome for all parties. They likely didn’t even realise there was a problem!

If you work in a high-noise environment and feel that noise is not being properly considered as a workplace hazard, you can contact your state’s workplace health and safety regulator to see how you can get that noise addressed.

If you’re lodging a complaint, it’s best to gather evidence that lends weight to your claims. That’s where NoiseNet can help. Our noise monitoring devices can gather comprehensive data on where noise is coming from, how loud it is, and what is causing it. And unlike most, we gather that information over prolonged periods of time to fully assess the impact of the noise. To learn more, check out https://www.noisenet.com/.