How to Monitor Noise?

Noise monitoring is frequently conducted on construction projects, industrial sites, and at entertainment venues where there is a risk of noise pollution to employers or the wider community. All sound that is harmful to human health or is annoying is considered noise.

The Primary Sources of Noise Include:

  • Machinery
  • Vehicles
  • Loudspeakers
  • Explosions

It is important to monitor noise to minimize the impact of your site on the environment and to demonstrate compliance with the law.

Noise is Monitored Using a Sound Level Meter (SLM)

This is to measure changes in air pressure, recorded in decibels (dB). Noise is typically measured by adjusting how a human ear responds to sound (A or C weighted responses). A sound level meter (SLM) can measure sound at different frequencies (called octave band analysis) and record sound clips to determine the source of noise pollution.

Two Types of SLM

There are two different types of SLM – Type 1 and Type 2. For environmental monitoring purposes, a Type 1 is recommended and ensures your monitoring project will comply with all types of noise regulations.

How to Monitor Noise1

There are Two Main Types of Noise Monitoring

The two types are instantaneous monitoring (handheld) and continuous monitoring (unattended):

Instantaneous Monitoring: uses a handheld SLM to take readings for short periods of time. This may be useful to get an idea of what the typical sound level from a source may be, or to check what noise is produced during worst case conditions (i.e. all machinery operating at the same time).

Continuous Monitoring: uses a SLM positioned at a fixed location to measure sound levels. This type of monitoring is used to alert a site when noise levels are above a compliance limit.

How to Monitor Noise2

Continuous SLMs should have the Following Features Address Community Health Concerns and Satisfy Stakeholders

  • A Type 1 SLM with octave band analysis
  • Automated data collection of real-time measurements and statistics (i.e. Leq, LA90, LAmax)
  • Weatherproof microphone designed for outdoor exposure
  • Alert notifications – Following a breach of your noise limits, your monitor should be able to send you an alert to address any issues
  • Sound clip recording triggered by noise pollution (mp3)