Simulating the acoustic performance of buildings
Using a 12-channel ambisonic 3D sound system, Arup’s SoundLab can produce the effect of an orchestra performing in a concert hall — or the acoustics of an office.
A concept developed by Arup makes it possible to simulate the performance of buildings from concert halls to offices before they are built.In concert venues, opera houses and studios, excellent acoustics is vital to the success of the building. In airports and railway stations, acoustics contributes to the general ambience and the intelligibility of announcements. In offices, museums and galleries, good acoustics has a key role to play in achieving a satisfying environment. We are quite used to the 3D modelling of buildings making it possible to walk or ‘fly’ through a building while it is still at concept stage. Now a similar facility is available for acoustics with the development by Arup of the SoundLab ‘immersive listening environment’. Perhaps the most dramatic use of SoundLab is to enable listeners to, for example, compare the same orchestra playing Handel’s Water Music in the Concertgebouw, Amsterdam, or in the Musikverein, Vienna, fully experiencing and understanding the subtle difference between the acoustics of each hall. They can also listen to the design for a new concert hall and compare it directly to the world’s best concert halls. The same facilities can also be applied to a wide range of acoustic design issues in buildings, enabling the client to understand the problem and determine the investment needed for reaching the optimum solution. It is also possible to optimise the speech intelligibility of a sound system in a large reverberant space, listen to the reduction in aircraft or road-traffic noise using various types of glazing construction or auralise the effect of a train passing under an isolated or non-isolated building. Rob Harris of Arup Acoustics says, ‘We can actually demonstrate why a space needs to be a certain form. Before, there was an element of trust involved, but now we can let architects listen to why a change in shape will improve the quality of sound. Before, it was black magic, but now it’s accessible to everyone.’ Listening rooms are available in London and New York, and one is soon to be opened in Melbourne. These sound-insulated rooms have low background noise levels and controlled internal acoustics to give accurate representation of the sound in auralised spaces — using a 12-channel ambisonic 3D sound system. Rob Harris continues: ‘SoundLab’s real value is that it allows an understanding of what the boundaries are in design terms so we can design better buildings. In addition, it allows clients to make value judgements on acoustic properties by using a subjective comparison of alternative building elements. After three years’ of client reaction in New York, the experience of Neill Woodger of Arup Acoustics is similar. ‘It’s where art meets science, allowing us to design with our ears and our emotional response. It has enable us better meet our clients’ needs, making the science of acoustics easy for them to understand and allowing them to make more subjective decisions on the acoustics of their building. What you hear in the SoundLab is very close to what you will hear in the completed building — greatly reducing the risks previously inherent in acoustic design.’ A SoundLab can also help the understanding of acoustic parameters. Difficult acoustic terminology an be demonstrated, listened to and understood. From prestigious concert halls to the public-address system in Terminal 5 at Heathrow Airport, from stadia and museums to office blocks — any space can be auralised. Recent and current uses of SoundLab include a new baroque concert hall in Boston, USA, the Sage Music Centre in Gateshead, which is due to open later this year, the new opera house in Oslo, the British Library Sound Archive Studios and Florence railway station, as well as several stadia worldwide.