Transurban, RMIT University team up to tackle road noise

Transurban is working with RMIT University on a landmark project to improve roadside noise ­management.

RMIT vice-chancellor postdoctoral fellow Jordan Lacey. Picture: Aaron Francis.

Toll-road major Transurban is working with one of the nation’s top universities on a landmark project to apply the technology used in top-of-the-range noise-cancelling headphones to help improve roadside noise ­management.

Melbourne’s RMIT University is engaged in a world-first motorway noise management study with Sydney’s UTS to pilot new approaches to the acoustic design of toll roads, including using noise cancellation, noise transformation and sound composition techniques to limit the impact on nearby residents.

Traffic noise along motorways is now primarily reduced by erecting large and expensive sound-­absorbing walls and insulating adjacent buildings to reduce noise to acceptable levels.

But RMIT vice-chancellor postdoctoral fellow Jordan Lacey has brought together several world-leading experts to conduct experiments into the potential shaping of motorway noise into new listening environments.

The work is being supported by one of Transurban’s $100,000 innovation grants, and input from local residents on the altered acoustics will be incorporated into the research.

Transurban operates the maj­ority of toll roads in Australia, with the greatest concentration of assets in Sydney and Brisbane, in addition to Melbourne’s ­City­Link.

It is also proposing to build the $5.5 billion Western Distributor motorway in Melbourne and is a key partner in Sydney’s $2.9bn NorthConnex project linking the Pacific Motorway to the M2 in the city’s north.

Transurban is also eyeing more road projects in the US.

“Inspiration for the research came from re-imagining possible uses of the often neglected and unused grasslands that sit adjacent to noise barriers on the non-roadside of motorways,” Mr Lacey said.

“The prospect of transforming these areas, through sound, and enticing the local community to engage with these spaces in new and interesting ways really appealed to me.

“This research is unique in that, for the first time that I’m aware, we’ve brought together different disciplines involved in the study of noise, and community perceptions of noise — acoustic engineers, sound designers and ethnographers,” Mr Lacey added.

“Ultimately we’d like to work towards the development of an ­expanded set of tools for industry and governments to manage noise, which could augment existing solutions.”

The only other time Active Noise Cancellation was tested on a roadside noise barrier was in Japan in 2004.

In the current project, involving two sites — one along CityLink, the other on Sydney’s M2 — a mixture of microphone and speaker arrays have been mounted temporarily on to motorway sound walls to produce new acoustic conditions.

“We are getting sound designers and composers to take a live feed of the traffic sound, apply it ­algorithmically to a computer program and come up with a different simulation of the traffic sound,’’ Mr Lacey said.

“We are looking at transforming the perception of sound at the point of listening. The background drone of a traffic sound could be transformed into something else.

“And with a passing truck or car horn, we might make it sound like a passing wave — that is, we apply effects that slightly alter the way that sound is perceived each time it is heard.’’

Mr Lacey said the “subtle shimmering” of the leaves of a tree or more modern soundscapes were also being tested in combination with noise cancellation technologies.

Michele Huey, Transurban’s group general manager strategy, said the project typified the early-stage innovation the company was looking to support through its innovation grants program.

“These are world-class researchers developing a very exciting and original concept with the potential to advance our industry,’’ she said.

The research project is due to be completed by July.