Environmental Noise Monitoring
Environmental noise is a major issue in most countries, especially in areas of high population, and the sources of noise and their adverse effects on our wellbeing are varied.
In terms of assessing the impact of these issues, we need to be able to make suitable noise measurements, or in some cases, monitor the noise levels for longer periods.
Industrial noise, for example, is a much more exact science, as you are interested in assessing specific noise levels and relating these to legislative or action levels.
Environmental noise is very different because the level of annoyance or nuisance can be very subjective and will elicit diverse reactions from different people.
Examples of typical noise sources:
- Industrial Sites
- Construction Work
- Road Traffic
- Animals (Dogs barking)
- Aircraft noise
- Entertainment venues
Environmental noise can also have different characteristics:
- Extraction Fans, compressors etc
- Road traffic
- Industrial Processes
- Industrial Processes
- Broadband (Noise that has a fairly even tone content and less annoying)
Tonal Noise (Noise that has dominant tone(s) that can be very annoying)
- ‘Whining’ machinery
- Low frequency noise that causes vibration within surrounding buildings etc.
- Wind turbines
Types of environmental noise monitoring
1. Basic noise level checks or ‘spot checks’
Often you need to take quick decisions and understand if there are likely to be any noise issues. By using a simple digital sound level meter such as the Pulsar Model 14 you have a cost effective, compact and ‘easy to use’ noise meter that can be easily transported, allowing you to make a quick judgement regarding noise levels. This is particularly useful where a more expensive instrument would be cumbersome and more prone to the risk of damage or misuse. Also check Models 41 and 42 from the Pulsar Nova range to perform basic noise level assessments,
The Pulsar Model 14 is supplied with a carrying pouch, windshield as standard to protect the microphone capsule and has two selectable ranges to allow you to quickly gauge both environmental and industrial noise levels. The instrument is compliant with IEC 61672 and can be supplied with an acoustic calibrator if you wish to verify your measurements – as really should be done.
2. Single but more detailed measurements
Environmental requirements and legislation vary based on your country, locality and specific circumstances.
Often a hand held integrating sound level meter such as the Pulsar Model 30 would be mounted on a tripod at a boundary position and, for example, a 15 minute measurement taken. Often it is necessary to make a series of similar ‘fixed duration’ environmental noise monitoring measurements and store these into the instruments memory (for subsequent analysis) for which the Pulsar Model 30 or Model 33 are ideal. The usual stored information may consist of the ‘A’ Weighted Leq, LN values, SPL values and perhaps 1:3 Octave Band information for tonal analysis.
Typical view of a 1:3 Octave Band Analysis using Acoustic Toolbox software.
3. Longer term environmental noise monitoring
Sometimes we need to monitor noise levels on an ongoing level and make longer measurements sub-divided by shorter measurement durations such as 5 minutes, 15 minutes or 1 hour. This allows us to look at, for example, a 24 hour period and find the average, background or maximum noise levels for every 15 minute period throughout the day. This gives us a much clearer picture of noise patterns and how they can be controlled to minimise their impact on the wider community. Often, lower noise limits will be set during the late evening and night due to the extra impact of any noise. For example, both Class 1 and 2 Nova sound level meters have a removable preamp which enables the meters to be used with microphone extension cables. These outdoor measurement kits transform the Nova sound meters into a longer term, outdorr monitoring system.
There are many engineering solutions available to reduce noise levels and by performing a 1:3 Octave Band Analysis before and after this work you can determine and report the effectiveness of such improvements.