Noise Levels
Noise is the variation of air pressure comprising compressions and rarefactions of longitudinal waves. It is the magnitude of the compressions and rarefactions that determine the noise levels. As the noise level increases the risk of Noise Induced Hearing Loss (NIHL) increases.
A person can generally perceive a 1 – 3 dB change in noise levels. However the perceptions of noise levels are different to the actual energy that the ear is subjected. The perception of noise levels double every 10 dB, however the increase in energy experienced by the ear is doubled every 3dB. When it comes to the potential for noise induced hearing loss, it is the noise energy level that is critical. The noise energy levels considered to be excessive when noise levels exceed LAeq, 8hr of 85 dB(A) and LC,peak of 140 dB(C).
A general rule of thumb for detecting excessive noise levels is if you have to raise your voice when talking to someone 1 meter away. Some common noise levels include:
|
140 dB |
Threshold of pain Jet Engine at take off |
|
110 dB |
Angle Grinder |
|
100 dB |
Nightclub Motorcycle |
|
90 dB |
Lawnmower |
|
85 dB |
Compliance A weighted noise levels for NSW WHS Regulations |
|
80 dB |
Alarm clock |
|
75 dB |
Vacuum cleaner |
|
70 dB |
Taking a shower |
|
60 dB |
Normal conversation |
|
40 dB |
Running water of a creek |
|
30 dB |
Library |
|
20 dB |
Leaves from the wind |
|
10 dB |
Pin dropping |
|
0 dB |
Threshold of hearing |
Noise levels can be steady state or impact. Steady refers to the continuous noise levels not varying by more than 6 dBa. Impact or impulse noise occur from a sudden peak in noise followed by an exponential decay which may cause acoustic shock.
For more information on noise levels, please contact one of Safe Environments occupational hygienists on 02 9624 2600 or visit our dedicated website on noise levels http://www.noisetesting.info/noise/
Noise News
Occupational Noise Assessments NoiseTesting.info - 28 April 2012
Safe Environments have released its dedicated website to noise testing and consulting services which can be found at www.NoiseTesting.info. The new website seeks to provide clear, transparent and objective information for employers, OHS professionals and workers alike to reduce potential health risks associated with noise exposure.
Workplace Noise Testing - 10 January 2012
Noise testing first requires a preliminary assessment to determine if sound levels are likley to exceed 85 dBA over the working day. This is conducted in line with AS/NZS 1269.1:2005 Occupational noise management – Measurements and assessment of noise immission and exposure Read more>>>
Occupational Noise Assessments - 26 August 2011
Safe Environments Occupational Hygienists provide occupational noise assessments to AS/NZS 1269. The noise testing measures sound levels and assesses exposure and provides control strategies to ensure the risk of noise induced hearing loss is minimised. Read more>>>