In designing any kind of architectural structure – homes, offices, hospitals, restaurants, airport lounges or leisure complexes – both architects and operators have to make sure they are creating an acoustically comfortable environment. Forgetting to pay attention to sound is a recipe for commercial disaster. In different types of buildings we want to minimise or maximise different types of sound. Concert halls and lecture theatres need sounds from some directions to be clear while other sounds and reflections must be suppressed. It is not merely a question of volume, in the majority of cases, an entire spectrum of frequencies matter, and they behave differently.
Sound control isn’t only important in buildings intended for aural performances, it’s crucial in all buildings. Consider speech intelligibility and trying to hold a hospital conversation beneath the roar of an HVAC system, the thud of heavy machinery or the growl of traffic on a nearby highway. Imagine trying to sell a home that rattles and rolls in unison with passing trains or aircraft ground movements.
Working in a modern large open plan office with hundreds of voices reflecting off hard surfaces is not dissimilar to working in a bar! All too often, expensive construction projects are greenlit without incorporating acoustic design from the outset. In many more, acoustic studies are only considered at a late stage when too many key design features are already detailed. The outcome is often a building unfit for purpose or one requiring very expensive remediation. For that reason, it is vital for all architects, developers and investors to embrace acoustics as part of the initial design concept. Broadly speaking, acoustic design usually addresses the key areas of; noise penetration, both inward and outward, and the control of sound reflections and reverberation.
The objective of an acoustic engineer is to determine which sounds (directions, frequencies and volumes) are useful and which are not, then developing the best possible sound profile in different locations of the building. Some sound pulses and wavelengths can accentuate each other, while others cancel each other out. Large flat surfaces make excellent sound mirrors – with good or adverse consequences. Uncontrolled sound reflections from walls can create a disturbing environment in which people trying to speak, or eat, are constantly distracted by other voices they hear around them. This happens all too easily in commercial buildings and public spaces. As each group raises their voice above the noise, the problem quickly escalates.
One trick of the acoustic engineer is to kill echoes with small curved edges that cause the soundwaves to scatter. In an auditorium, a single large curve can be used to amplify a sound from one particular location, improving clarity for numerous listeners. The Romans and Ancient Greeks were enthusiastic exponents of this technique. Every material and texture reflects different frequencies and absorbs others. Soft and curved materials tend to absorb, suppressing sound, while hard flat ones resist penetration, reflecting sound instead. By combining absorptive materials and noise control products which stop the transmission of sound between spaces, such as acoustic doors and windows, the quality and appreciation of a space or built environment can be substantially improved.
IAC Acoustics is a global provider of acoustic engineering solutions with more than seventy years of experience. Every kind of business, industry and commercial development needs to understand their acoustic architecture and design. We help support that requirement working with acousticians, architects and consultants to deliver effective noise control solutions to a wide range of market sectors.
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