Experts wanted to drown out a Maltese problem: noise

Malta’s environmental watchdog is seeking experts who will generate a study to propose various noise abatement measures around the islands, as well as acoustic design guidelines for both old and new homes.

The study will not only find out ways of reducing noise pollution, but also peak into the crystal ball to find out how high traffic, short routes, a hot climate and the tendency to leave windows open, make noise a bigger issue for Malta.

“Noise has been found to have negative impacts on human health, making an improved noise climate highly beneficial. There may also be potential cost savings on healthcare for residents in the surrounding areas where the interventions will be proposed for installation,” ERA said in its call to tender for the project.

By 2030 Malta is obliged to reduce the share of people chronically disturbed by transport noise by 30%.

The authority wants to know which noise abatement measures will reduce sound levels, particularly from road traffic, as well as decreasing the number of people exposed to traffic noise, and also identify the ideal locations where measures could be best implemented.

“Without underestimating the importance of noise from aviation and industry, the foreseen increase in road traffic is a noticeable contributor to the increase in future noise levels,” ERA said. “Moreover, road traffic noise is a major environmental problem, predominantly in urbanised areas.”

From a strategic noise mapping exercise compiled by ERA in 2016, it emerges that 24% of the population within such agglomerations are exposed to high noise levels from road traffic sources that are above 55 decibels, the daily annual average.

But due to the complexity of urban development in Malta, where a number of major roads are located in close proximity to sensitive receptors such as schools, hospitals and residences, road transport noise is a common occurrence.

“It is a known fact that noise from roads with high traffic counts has a major impact on the environment and nearby areas as it influences everyday life, leading to annoyance, distraction and sleep disturbance,” ERA said, adding that noise barriers could help residents experience better quality of sleep, better conversations and even leave windows open for a longer period.

Noise barriers are one of the most effective methods of reducing road traffic noise, by acting as an obstacle to sound waves from engine noise as well as rolling, tyre-road noise. Although sound waves are not completely absorbed, these are minimised through diffraction around and over the noise barrier, usually reducing overall noise levels by up to 10 dB.

Noise barriers can be merged with sustainability concepts, such as green walls that can improve air quality and abate pollution generated from heavy traffic.

Recently, Malta implemented its first noise barriers along the infrastructure upgrade of the Kappara Junction.

Noise diffractors, another proposed measure, reduces or redirect sound waves in a specific area, using grooves that scatter the sound alongside the road, in an upward direction. Its big advantage is that the noise-reducing effect remains the same throughout its whole life span, around 30 years. It is also possible to combine diffractors with noise barriers.

Porous asphalt

Another solution could be the use of low-noise asphalt, whose microscopic grooves are a contributor to noise resonance.

Using porous asphalt – originally developed to enhance skid resistance during braking – this material can reduce high-speed traffic noise by up to 5 dB. “Proper installation of road surfacing is crucial for achieving maximum noise reduction... Under optimal conditions, when using pavers or ceramic bricks, noise reduction of up to 9 dB is possible. Implementing such noise-reducing measures would create a more pleasant living environment around paved roads and potentially lead to increased business and property values.”

Currently, the materials required for alternative road surfaces are not readily available in the Maltese market, necessitating their importation and creating a supply chain, which could result in a slower implementation of the installation and additional costs.

ERA said there is also a lack of widespread knowledge and expertise in Malta regarding the proper installation of these road surfaces to fully utilise their potential.

Furthermore, the use of this kind of asphalt will also mean added traffic calming and traffic management measures to control speeds and prevent excessive wear and tear, similar to the deterioration experienced by asphalt roads.

What is acoustic design?

Good acoustic design involves the use double or triple-glazed apertures or soundproofing, as well as roof and façade insulation, and acoustically treated ventilation during the design and construction of residential developments to avoid as much as possible unnecessary high levels of noise.

The design process creates a better living environment and a space that is both comfortable and attractive to live in, especially in areas that are located in hotspot areas and prone to heavy traffic and high levels of noise that may be harmful.

ERA wants a recommended approach outlining the minimum requirements for effective acoustic design interventions within different residential developments, especially amongst practitioners in this sector, to provide a better living environment.

The guidelines should not only address new future residential developments but also existing buildings, in particular those that are located in noise hotspot areas.

“Although it is imperative that good acoustic design is considered during the early stages of the development process, old and existing developments can also introduce such a concept through the retrofitting of existing apertures or modifications by means of the installation of proper interventions,” ERA said.