Independent report demonstrates no change in infrasound

The recorded infrasound levels at the Macarthur Wind Farm, jointly owned by AGL Energy Limited (AGL) and Malakoff Corporation Berhad, in South West Victoria have not changed since construction of the wind farm, according to a new independent report by Resonate Acoustics. 

AGL’s General Manager Power Development, Scott Thomas, said AGL voluntarily commissioned the report to help alleviate community concern regarding noise. 

The research measured infrasound [i] and low frequency noise [ii] at residences located 2.7 and 1.8 kilometres from the nearest turbine before any turbines were operating, when approximately 105 of 140 turbines were operating and when all 140 turbines were operating.

“AGL has undertaken the most extensive and rigorous research by a wind farm operator in Australia and also has gone above and beyond its regulatory requirements,” said Mr Thomas.

“This research demonstrates that there was no measurable change in the infrasound levels measured before and after construction of the Macarthur Wind Farm.

“We would like to thank and acknowledge our neighbours for assisting with this important study. Internal noise monitoring is quite intrusive and we appreciate their cooperation,” he said.

The noise monitoring equipment was placed within household bedrooms facing the wind farm during each stage of monitoring. The equipment stored G-weighted sound pressure levels and linear sound pressure levels to enable assessment of the infrasound and low frequency noise levels.

The assessment methodology provided a comparison between the baseline or pre-operational data and the operational levels after construction.  This involved a combined measurement period of over 90 days.  Measured infrasound and low frequency noise levels were also assessed against best practice international and Australian guidelines.

Resonate Acoustics’ Infrasound & Low Frequency Noise Operational Monitoring report was also reviewed by internationally renowned low frequency acoustic expert, Dr Geoff Leventhall.

In addition to the infrasound monitoring, AGL undertook noise monitoring at 25 neighbouring properties between October 2012 and May 2013, since the first operation of a wind turbine at Macarthur Wind Farm, in order to confirm that the wind farm is compliant with noise regulations.

The Resonate Acoustics's Infrasound Low Frequency Noise Operational Monitoring report and all of AGL's noise monitoring data from the compliance noise assessment is accessible on AGL’s Macarthur website.

About AGL

AGL is one of Australia's leading integrated renewable energy companies and is taking action toward creating a sustainable energy future for our investors, communities and customers. Drawing on 175 years of experience, AGL operates retail and merchant energy businesses, power generation assets and an upstream gas portfolio. AGL has one of Australia's largest retail energy and dual fuel customer bases. AGL has a diverse power generation portfolio including base, peaking and intermediate generation plants, spread across traditional thermal generation as well as renewable sources including hydro, wind, landfill gas and biomass. AGL is Australia's largest private owner and operator of renewable energy assets and is looking to further expand this position by exploring a suite of low emission and renewable energy generation development opportunities.


[i] noise at frequencies lower than 20 Hz

Infrasound is a very low frequency noise (less than 20 Hz) which is always present in the environment, arising from natural sources such as wind and waves, industry and typical household activities.  We are all constantly exposed to infrasound through the functioning of the human body, such as breathing and our heart beat.  Infrasound is neither audible or perceptible unless at very high levels.

[ii] noise from frequencies of 10 Hz to 160 Hz

Low frequency noise is defined as between 10-160 Hz and overlaps the infrasound range.  People are often exposed to low frequency noise in the environment, as it is a characteristic of human life.  In a rural environment, typical sources would be vehicles, agricultural machinery, water pumps, compressors and natural sources.