Synopsis—The Problem and Our Proposed Response
Over the past twenty years the Australian Noise Exposure Forecast (ANEF) system has been used in four key ways. It is used to delineate where and what type of development can take place around airports; to determine which buildings are eligible for insulation around Sydney Airport; for technical assessments of airport operating options in Environmental Impact Statement (EIS) processes; and as a tool for providing information to the public on noise exposure patterns around airports.
It has been and continues to be successfully used in the first three of these roles. However the Department considers that there are significant limitations in using the ANEF as a way to describe aircraft noise exposure to the layperson.
While the populations with the highest aircraft noise burdens live within the 20 ANEF contour the majority of noise complaints that are received are now coming from persons living outside the 20 ANEF contour. Traditionally the residents of these areas have been given little information on aircraft noise through the ANEF system other than that the area is considered ‘acceptable’ for new housing. This type of approach has at best proven unhelpful and at worst has sent completely the wrong message. Some people living outside the 20ÊANEF contour have been given an expectation of receiving little or indeed no aircraft noise and as a consequence find the levels of noise actually experienced to be ‘unacceptable’.
In simple terms people want to be told about aircraft noise exposure in their own language—where the flight paths are how many movements what time of the day etc—but the official response has been to provide information in the form of a single figure ANEF value. Not unnaturally there has frequently been a breakdown in communication between the ‘noise expert’ and the community which we consider has been at the expense of both parties.
This paper describes approaches that the Department of Transport and Regional Services has developed in an effort to address these communication problems. The proposed solutions are simple—no doubt some will characterise them as simplistic. In essence the Department is trying to encourage airports/acoustical professionals/planners to use the same terminology that non-experts use when talking to each other. This has led to the development of descriptors based on treating aircraft noise as a series of single events rather than through cumulating and computing average noise energy which is the basis of the ANEF.
It is argued in the paper that these descriptors enable us to move beyond the conventional thinking on aircraft noise where on one side of the line the noise is described as being ‘acceptable’ while on the other it is termed ‘unacceptable’.
The descriptors enable people to ‘visualise’ what aircraft noise will be like. Armed with this information they are in a much better position to make a decision whether they are likely to find future noise ‘acceptable’. For example a noise sensitive person will be greatly advantaged when deciding on whether to make a house move if they have access to this type of information rather than simply knowing that the area is exposed to say less than ANEF.
The same principle applies to situations where an airport is proposing to introduce changes such as a new runway which would if approved result in major changes to the aircraft noise exposure patterns over neighbouring communities. Providing ‘real’ aircraft noise information for all of the areas likely to be subject to changes in aircraft noise enables the community to actively and meaningfully participate in any public consultation process. It also gives the decision makers a much clearer picture of what the outcomes will be if they approve the project. In effect it enables a community to decide on what it believes are ‘acceptable’ operating and flight path arrangements for its airport.
The broad thesis being proposed by the Department is that it would be to the advantage of all parties—airports industry and the community—if we moved beyond using the ANEF system as an information tool (but retain it for its other uses) and commenced producing ‘real’ aircraft noise information on a regular basis. To this end it is suggested that Australian Standard AS2021 needs to be enhanced to provide a basis for the provision of better information to address the aircraft noise issues that are now arising at a number of Australian airports.
This paper is not an attempt to replace the ANEF system as a planning tool. The ANEF system continues to be the most technically complete means of portraying aircraft noise exposure and the Department is not proposing any changes to the land use noise exposure and the Department is not proposing any changes to the land use noise exposure and the Department is not proposing any changes to the land use planning principles and restrictions embodied in Australian Standard AS2021.