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Sound Level Meter

Also called a decibel meter, a sound level meter is an acoustic measuring instrument used for assessing the sound environment. The noise level measured is expressed in decibels.

What is a sound level meter?

Put simply, a sound level meter is a device that measures noise and its spread. Equipped with a microphone to capture audio, it converts sound pressure into a value expressed in decibels in order to quantify the noise level as perceived by the human ear.

Why use a sound level meter?

A sound level meter is useful in many scenarios, both professional and private, to measure noise pollution, check compliance with noise standards and assess disturbances. Sectors that use sound level meters the most are the construction industry, public works, the transport sector and industry in general.

A sound level meter can be used to check that noise level standards are being met or, in the case of an occupational physician, to make sure that exposure to surrounding noise does not create additional stress for workers or to determine whether hearing protection needs to be worn at work.

Local policies or scientific studies sometimes also require the use of this type of instrument in studies on noise pollution or noise levels caused by traffic or urban developments.

Lastly, entertainment professionals sometimes use a sound level meter as an applause meter to gauge how successful an artist is with their audience. Bars, discos and leisure establishments also need to check that their noise level doesn't violate standards.
Even private individuals might use a sound level meter. Noise pollution is an increasingly common subject due to the fact that it's a major public health issue, with noise exposure being a significant stress factor and notably having an impact on sleep quality. This measuring device can also be used to highlight a noise disturbance problem caused by neighbours or a noisy business nearby. An assessment of noise exposure levels over an extended period can be submitted to the appropriate authorities and help put an end to excessive noise in accordance with legislation.

More simply, anyone might want to measure the noise of road or air traffic near where they live, for example to decide whether it's worth fitting double glazing or investing in more effective sound insulation. Discover all our products

How to choose a sound level meter

You'll need a different type of sound level meter depending on whether you're a professional or a private individual, whether you want indicative or regulatory values of noise levels and depending on its intended use. Lots of different devices are available, all of which have different measurement accuracies and characteristics. Below are some pointers to help you choose:
  • Analogue or digital sound level meter? Analogue devices indicate measurements via a moving needle, while digital instruments have a digital dial that provides more accurate values.
  • What size of sound level meter should I get? If you want to carry the device around, buy a light and compact model that's easier to transport. You'll also save space at home and save on delivery costs!
  • Indicative or regulatory values? For home use, indicative figures may be enough. However, if the device is being used at work or to check compliance with standards, regulatory data is required.
  • Battery life: if you're buying a portable device, taking measurements over a longer period of time or regularly using the instrument, it's best to get a product that has longer-life batteries. This isn't so important if you're only taking occasional measurements.

    * Accuracy: your device should state its measurement accuracy. Shown in decibels, this indicates the sound level meter's margin of error. For domestic use, an accuracy of + or - 1.5 dB is usually sufficient. You also need to consider your instrument's resolution. This indicates whether the noise level is shown in units or decimals. Figures to a tenth of a decibel are enough in most cases.
  • Measurement range: this is between the lowest value measurable (usually around 30 decibels) and the highest, usually around 130. However, in some cases you might need a wider range.
  • Weighting: the human ear does not perceive all sounds in the same way depending on their acoustic frequency. To ensure that the linear perception of sound level meters matches that of humans, frequency weighting filters need to be applied. Rather than indicating the objective sound level, the measurements given by these instruments indicate sound levels comparable to those perceived by the human ear according to their frequency. Sound level meters have three frequency weighting filters: weighting A, C and Z. If this data is important to you, choose a sound level meter that measures all three frequency weightings at the same time.
  • Recording device: when choosing from the various products available, it's best to buy a model that has a recording device. This will allow you to save each noise level measurement. This recording function is very useful for making comparisons or, if the instrument runs software, for creating a curve and observing changes in the noise data using software on your computer.
  • Microphone: choose a device that has a good audio microphone. This is an important basic feature for capturing the sound pressure from all sides and obtaining a reliable measurement of the noise exposure.
You now have all the information you need to carefully choose the right sound level meter for your needs from all the audio instruments available on the market. In the long run, it's likely you'll find that a premium digital product with software than can produce a curve is a good option. Bear in mind that products designed in France and lower delivery costs are also important factors!

What can you use instead of a sound level meter?

Is measuring noise pollution not your job or are you looking for specific devices to check compliance with a French standard? Products are now available that, despite not being a replacement for a professional audio device like a sound level meter, are nevertheless suitable for measuring noise levels.
  • Smartphone apps: using your phone you can take SPL (sound pressure level) measurements and determine your exposure in a few taps. Nevertheless, the microphones are rarely very good quality.
  • Some weather stations have an SPL sensor that measures noise levels. For example, the Netatmo station has a measurement range of 35 to 120 dB. The data is then available in the app, along with a feature that allows you to produce a curve from the data in your preferred app on a smartphone or tablet.

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