Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Simulating future noise in order to prevent it

23.02.2016

Noise is disturbing and can be harmful to health. Empa researchers have now succeeded in simulating road noise by means of «auralisation». The aim is to make noise audible along traffic routes that are merely in the planning stage – and thus include countermeasures at the same time.

Auralisation is understood as making audible those sound events that will only occur in the future. Until a few years ago, it was mainly used by interior designers for optimising room acoustics.


Using this experimental set-up, the Empa scientists recorded the tyre noises they have taken into account as a source in the auralisation model, alongside the engine-related driving noises.

In Empa's «TAURA» project funded by the Swiss National Science Foundation (SNF) a research team around Reto Pieren is now working on an auralisation model, which simulates the noise of a car accelerating past an observer. This model thus makes it possible to take account of precautions to reduce noise, even in the planning of road construction projects.

Developing such an auralisation model is easier said than done. The noise caused by a car speeding past originates from different sources, which have to be entered into the «emission module» in the computer model. Firstly there is the engine that roars in the ears, particularly at high speeds. Although speed, vehicle type and driving style also influence the engine-related driving noise.

Then the tyres also generate noise as they roll along the road. This is largely dependent on the type of road surface and make of tyre. Pieren and his colleagues would like in future to add further sources of noise into their auralisation model, such as the effect of different road surfaces and wind noises.

Thousands of parameters – that is how complex the noise of vehicles can be

The researchers firstly had to identify the extent of all these influences. To this end, they recorded the driving noise of various makes of vehicle, for instance of a VW Touran, a Ford Focus 1.8i or a Skoda Fabia. These measurements were taken from several microphone positions and at different speeds. The researchers also varied the tyre models, engine load and revolutions per minute.

They then extracted the sound characteristics from these recordings and transcribed these as parameters in their auralisation model. They ended up with a total of several thousand such parameters, which cause a completely different driving noise depending on interaction.

Although even this was not sufficient: next they had to account for propagation phenomena such as the Doppler effect, sound absorption in air and reduction in noise due to the distance between the source of the noise and the observer. An observer will perceive noise differently depending on his or her position in relation to the source of the noise and how each moves relative to the other. We all know the Doppler effect from our daily lives: the siren on an emergency vehicle has a high pitch whenever the vehicle is approaching and a comparably lower pitch when it is driving away again.

How irritating do we perceive noises to be?

The modelled signals finally have to be transformed into sound via headphones or a pair of speakers. Noise first arises in our consciousness, however, so is perceived differently from listener to listener and is not easily registered in physical measurement units. That is why test subjects were asked to listen to the simulated driving noises and make statements about their irksomeness, the level of noise induced impairment. Objective relationships can be established whenever several test subjects have assessed different noises according to their irksomeness, although noise is a subjective factor.

Noise has a different effect on human beings depending on the time of day, health condition and age. Accordingly the consequences for health extend from intermittent sleep deprivation through to an increased risk of cardiovascular disease. Noise reduction measures must therefore be taken into account when planning residential and industrial zones and traffic routes in order to prevent such impairment. This is where town planners, political decision makers and the public need indications of the anticipated noise emissions. Standard measures can be calculated nowadays – but auralisation can help with evaluating new ideas for noise optimisation. This is how Empa researchers contribute to noise reduction using their auralisation model.

Also of interest to the research community

Besides the practical, there is also a scientific benefit. There was no such detailed auralisation model available for simulating road noise before Reto Pieren and his colleagues started their research. In particular the simulation of accelerating vehicles is new. To this extent the research group is involved in pioneering work in the field of auralisation. The scientists plan to conduct initial experiments with sample recordings in their in-house audio laboratory within the next few weeks.

Weitere Informationen:

http://www.empa.ch/web/s604/-/auralisierung-von-beschleunigenden-autos

Cornelia Zogg | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Further information:
https://www.empa.ch

Further reports about: Doppler effect Empa Simulating computer model high speeds reduction traffic routes

More articles from Architecture and Construction:

nachricht Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH

nachricht Designing Architecture with Solar Building Envelopes
16.01.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>