Sound pressure levels associated with certain activities or equipment (source: World Atlas – What is Noise Pollution)

Noise can be defined as “unwanted sound”; audible acoustic energy that adversely affects the physiological and/or psychological well-being of people or which disturbs or impairs the convenience or peace of any person (affecting their quality of life). One can generalize by saying that sound becomes unwanted when it:

However, it is important to remember that whether a given sound is “noise” depends on the listener or hearer. A person playing loud rock music in their living room hears only music, though his next-door neighbor hears nothing but noise. However, noise does not need to be loud to be considered “disturbing”. One can refer to a dripping tap in the quiet of the night or the irritating “thump-thump” of the music from a neighboring house at night when one would prefer to sleep.

Only considering the “intensity” of a sound (or noise) level (the sound pressure level), some people may become annoyed without hearing any noise (perceived impacts), whereas others may not even be reporting noise to be a concern, even when subjected to very high levels. How a receiver may perceive a noise impact, or determine the “severity” of a noise annoyance include:

 

 

 

As “noise” is perceived differently by different people, there are legislative guidelines that can be used in South Africa to assess whether a certain sound can be defined as noise. This includes:

Each of these regulations is relevant for proposed projects to be developed within the various provincial areas, with the key points discussed in separate posts. These regulations set the legislative background, allowing a qualitative means of defining a “disturbing noise”, with the process of defining a “disturbing noise” roughly by:

  • The defining of the acceptable sound levels (or a zone sound level or rating level): There are two accepted procedures to define this, namely the measurement of ambient sound levels using a sound level meter (considering the developmental character), or obtaining a zone sound level as defined by SANS 10103:2008 (or as assigned by the Provincial, Metropolitan or local Municipality).
  • The measurement of the noise level using an accepted protocol (or the calculation of the potential noise level if measurements are difficult) near the source of noise, or near a receptor complaining about a potentially annoying or disturbing noise;
  • Using the correct noise control regulation to assess the change in either ambient sound level, or how an intruding noise influences the zone sound level.

These criteria are used during the investigation of a noise complaint as well as for a noise impact assessment. Any mistakes in any of these steps could result in a project proceeding but:

  • Potentially disturbing noise is registered and expensive noise pollution control measures are required; or
  • Noise levels were overcalculated with the project developer unnecessarily implementing expensive noise pollution control measures.

With more than 15 years of experience on various projects, EARES has both the experience and knowledge to assist our clients in defining ambient sound levels, potential noise levels as well as the associated noise impact, allowing for appropriate noise control measures.

Should you have any questions you are welcome to contact EARES.

 

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