Sound Designs: Making Buildings Better through Acoustic Design
Stop. Listen. Do you hear anything? Perhaps the sound of quiet conversation or laughter, the distant thrum of traffic, the buzz of fluorescent lighting, or the whirring of a fan in your air-conditioning unit. These are all sounds that are influenced or determined by architectural design and building acoustics.
Buildings and infrastructure come with their own noise and acoustic patterns and can be designed using architecture, materials, and computer simulation to make them more productive. Whether creating a public address system that can be clearly heard in a busy airport, minimizing traffic noise heard in an office, or building a concert hall where the quietest sounds can be listened to clearly–all of it can be done before a brick is laid.
Design and architectural companies can now create a structure’s auditory profile from the ground up. Among them global firm Arup, whose SoundLab is made for acoustic consultancy. Projects include creating sound simulations for the UK’s high speed rail HS2 project to help minimize noise–using sound barriers and low-noise pantographs that attach the train to overhead electric cables–and revolutionary stage design for Icelandic singer Bjork’s Cornucopia tour.
SoundLab creates computer-simulated ‘auralisations’ that allow clients, architects, and building users to see and hear how structures will sound. “People are becoming more and more aware of the role that good sound, and the impact that detrimental noise has on their performance,” says Arup acoustic consultant Raj Patel.
Noise can actually make us sick. Loud road and air traffic sound is linked to greater risk of heart attack, cardiovascular disease, and stroke. The World Health Organization says traffic noise alone harms one in three people in Europe, and one in five are regularly exposed to nighttime sound levels that could damage physical and mental health.
Psychophysiological effects include disturbed sleep, annoyance, and changes in social behavior. Noise can interfere with people’s daily activities at school, work, home, or in leisure time and can diminish performance or increase medical visits.
Showing how acoustic design reduces noise exposure and enhances buildings was practically impossible to do until the late 1990s because of lower computer processing power. But building upwards from drawings and traditional scale models, Arup created the first SoundLab tool by positioning loudspeakers inside a small room in 1998.
Auralizations and visualizations are now created using real room recordings and sophisticated computer modeling. Acoustic signatures, called impulse responses, are generated from different points in the structure using sounds recorded in an anechoic chamber–a sound-isolated room that is completely echo-free. Virtual reality tours then allow people to see and hear what the building will sound like.
Techniques like these have been used to construct a huge variety of different structures. Allowing the public to hear how upgraded high-speed trains sound paved the way for the UK’s multi-billion dollar HS2 project.
Acoustic design formed a Yale University health center where patients could talk to doctors without being overheard, allowed people to hear how wind farms in Wales and Australia would sound, and created floating box-in-box TV broadcast studios shielded from low-flying airplane and motorway noise.
Sound designing urban environments shapes the landscape for the better by helping engineers and builders at the planning stage, adds Patel. “By using auralisation techniques, buildings can be finely tuned, with a big impact on sustainability,” he said. “It saves money by not oversizing spaces, or overusing and adding materials that are unnecessary.”
Building for Sound
Commuters ride an escalator at the newly opened 96th Street station on the Second Avenue subway line in New York, U.S., on Sunday, Jan. 1, 2017.
According to Raj Patel, the way a building sounds usually varies from space to space, and should be tailored to the functions expected to take place within it. Usually, three things need to be considered together:
- Room acoustics–the shape, form, dimensions, volume, and materials are all crucial to achieve acoustics that are tailored to the building’s function.
- Sound and impact isolation–control of sound transfer from the outside into the building, and between different spaces in the building.
- Background sounds–setting and achieving appropriate sound levels from building systems, eg.., mechanical, electrical, and plumbing.
Quiet doesn’t always mean better. For example, if the background sounds in an office space are too low, then sounds from outside the building or from people around you can become intrusive, making it hard to concentrate. But in a music studio or concert hall, quiet is important to ensure that you can hear both the quietest and loudest sounds, usually referred to as dynamic range.