Many airports across the globe are to be commended for their efforts to minimise airside noise, though a large percentage of residents living in any given gateway’s locality may well argue that they don’t go far enough. Arne Berndt, owner/adviser at mapping software company SoundPLAN International, offers his thoughts on how airport operators can minimise the noise that troubles those on and around airport ramp areas
How big is the problem of noise at airports?
Airports bring many economic benefits, providing major transport hubs for millions of business and leisure travellers, as well as economic benefits and job opportunities for the local region.
According to a report by Air Transport Action Group (ATAG), aviation’s contribution to global economic impact is estimated to be worth US$2,960 billion, equivalent to 8% of world Gross Domestic Product (GDP). However airport noise is, understandably, a significant issue for those in neighbouring communities, so its control is an important factor in airport development.
Noise within the airport airside environment includes not just the sounds of aircraft taxiing, starting up and landing, but also sound from the ground operations of engine test and run-up, auxiliary power units, the rattling of baggage handling equipment, air conditioning, airside maintenance works and traffic sources to and from the airport.
Dealing with airport noise is complex and is the subject of ongoing research efforts. Governments, regulators, the airlines, manufacturers and other associated parties have helped to develop a variety of programmes to improve industry knowledge of the impacts of noise and to find ways to resolve them, but further developments are needed.
Noise reduction is important for environmental purposes, but also to ensure companies are meeting health and safety compliance rules and regulations. Airports are applying a number of steps to curb noise pollution: for example, by setting limits and restrictions over air traffic volumes, introducing quieter engines and building sound barriers, as well as establishing more appropriate green belts around the airport boundary walls.
How can noise be accurately mapped out?
Modern noise mapping programmes can play a vital role in ensuring measures to mitigate airport airside noise will be effective. They make it possible to model complex situations and the various scenarios – such as aircraft taxiing and landing, along with traffic to and from the airport – and to use them to assess nuisance noise and plan mitigation measures.
The more information and data gathered the better, as this is crucial in the fight against noise pollution. With mapping software it is possible to produce graphical representations of noise contours using colours to depict the different levels, making the information accessible to the general public as well as scientists and engineers.
Sound maps can show past, current and predicted future levels of noise emissions thanks to the data that is entered into the software. The maps can then be used by airports to plan mitigation efforts and show improvements in an easy-to-understand format. Conversely, planning authorities can use them to show the noise contours for a new airport or expansion of services.
Using this type of software to model the noise of buildings, infrastructure and transport both at the planning stage and for existing structures is widespread in many countries. Noise mapping software and the predictions it produces are now a valid and important part of the process of ensuring citizens are protected from excessive noise, for instance.
So, mapping software calculations can add to simple measurements?
Measurements only show the overall level of noise, not the levels of emissions that come from any individual source. Using sound-mapping software, problem areas can be isolated and tackled.
Using measurements means that noise is only recorded as it occurs at a specific geographic point. It is not always possible to identify the source of that noise or the direction it is travelling. Mapping software, in contrast, can calculate the noise levels at a range of locations and from multiple sources.
When planning a new airport or an existing gateway’s expansion, the most accurate way to assess the levels of noise is to forecast them using mapping software. Once the noise source is in place measurements, or a combination of the two methods, may be preferable.
Why should we be worried?
A significant, but unseen, danger to staff is exposure to excessive noise. This can have an immediate effect or a pernicious long-term impact on health. Hearing loss is one of the most significant occupational health issues across the world, which should come as little surprise given the range of jobs using noisy equipment or taking place in loud environments.
Hearing loss can be immediate on exposure to a particularly loud or sudden noise. But gradual hearing loss, that may go undetected for years, is no less devastating. We often take our hearing for granted, but its loss is truly life changing. Even a temporary loss can have significant consequences, especially on our ability to communicate.
As momentous as hearing loss can be, it is not the only health impact to be concerned about. Excessive noise can cause a variety of physical and psychological impairments, including sleep disturbance, cardiovascular disease and stress. It can also increase the chance of workplace accidents and lead to communications issues.
The risks are not just to workers’ health. Businesses’ productivity, reputation and legal standing can also be dramatically impeded if proper mitigation measures aren’t put in place to protect people from excessive noise. This is not a matter to be taken lightly and noise should be part of every business’s risk analysis and planning processes.
How much is too much noise?
Across the world it is generally recognised that the noise exposure limit is 85 decibels (dB). To put that in perspective, that is quieter than a hand drill. A hammer drill is about 114dB and a pneumatic drill 119dB. It is worth remembering that most people perceive a sound to be twice as loud for each increase of 10dB. A pneumatic drill is therefore more than three times as loud as the recommended exposure level.
Personal protective equipment (PPE) – whether ear plugs or muffs – plays a key role in reducing unnecessary noise exposure, and a noise contour line should be established wherever people will be subject to levels above 85dB. Beyond this line PPE should be mandatory. Noise maps can help accurately establish where this line goes, both inside and outside a building.
Sound maps can also reduce the need for PPE in the first place, by showing where mitigation measures, including barriers and replacing noisy equipment, can help reduce overall airport noise levels.
What is standard practice in terms of acoustic standards?
To be fully effective, all noise modelling software relies on agreed acoustic standards. These allow noise simulation results to be compared, as calculations must be carried out in accordance to one of the national or international standards.
In accordance with Article 6.2 of the Environmental Noise Directive 2002/49/EC (END), the European Commission developed Common Noise Assessment Methods (CNOSSOS-EU) for aircraft, road, railway and industrial noise to be used for the purpose of strategic noise mapping.
Are we getting somewhere?
Airports need to show they are taking the issues seriously and work with the airlines to ensure effective mitigation steps are taken. Mapping software can play a vital role in helping to plan future mitigation options and clearly demonstrating improvements. This not only enhances the affected residents’ lives and worker safety but also improves the perception of the airport more widely.
Improved aircraft technology and sound insulation will ultimately be responsible for resolving the nuisance noise associated with airside airport noise. Setting and maintaining consistent standards will ensure that mapping software can paint an accurate picture of the noise situation to base those developments on.
We’re some way away from noise not being an issue in the aviation industry, but if those responsible for aviation development have the right attitude, there are numerous steps that can help reduce noise, protect staff and the environment and ensure residents don’t suffer unnecessarily.