When it comes to workplace or environmental design, acoustics have traditionally taken a back seat to aesthetics. Architecture has had a love affair with glass, steel and concrete for decades. The use of high, vaulted ceilings and open lines of sight has permeated almost every aspect of our lives, from auditoria to classrooms, restaurants to offices.
The trouble is, although these spaces might look great, they often sound terrible. The longer we spend in a poor acoustic environment, the more profound its impact on us. Take the open plan office as an example. Sure, a blank canvas allows people to put their stamp of individuality on a space, but in an effort to break down barriers to communication and collaboration, designers have created another problem. Noise.
Poor acoustics affect behaviour
Noise pollution in the workplace has a significant impact on performance. Research consistently shows noise contributes to higher levels of stress, absenteeism and illness, and lower levels of concentration and productivity.
In a busy office we are beset by the ringing of phones, the clicking of keyboards and the conversation of colleagues. As these sounds echo across the room, they create an invisible web of noise that becomes distracting. Our response is often to add to the problem by raising our voices to be heard above the din, a reflex action known as the Lombard effect.
Of course, the negative impact of poor acoustics isn’t limited to the workplace. Diners in restaurants struggle to be heard above the mix of clatter and chatter. Audiences in conference venues struggle to hear presenters and students in classrooms lose their concentration too easily.
In fact, poor acoustics have been linked to under-performance in education for decades. Controlled testing of students from primary school age to post-graduate education has shown that noisy environments impair a student’s ability to perform a range of written and verbal exercises. For students with special learning needs, this impairment becomes more pronounced.
A revolution in acoustic treatments
Walls, ceilings and floors are often built with cost and resilience in mind, but rarely is acoustic performance high on the agenda. Or should I say was? Because environmental design has begun to undergo what can only be described as a quiet revolution.
It may seem obvious, but sound travels. Often in ways you don’t appreciate. Whether you are designing for a new building or looking to refurbish an existing space, there are a few, simple acoustic treatments you might like to consider.
Wall and ceiling installations that use sound-absorbing materials with a high Noise Reduction Coefficient (NRC) can have a major impact on acoustic performance. The NRC of any material will be expressed as a decimal between 0 and 1. The higher the number, the better the material is at absorbing sound. For example, a material with an NRC of 0.5 will absorb half of the sound that hits it. Better-performing materials with an NRC of 0.75 or above will eliminate more sound.
When it comes to acoustic solutions, architects and interior designers can choose from a range of baffles, stretched-fabric panels, 3D wall and ceiling panels, or sustainably manufactured wall and ceiling tiles made from PET.
Be careful when using acoustic materials not to over-engineer the environment. There is such a thing as too quiet.
Sound masking technology is sometimes used to offset background noise, or to avoid a space being too quiet. However, you may find the effectiveness of sound masking is limited to areas with a constant sound profile. Also, adding another layer of sound within the environment, whilst evening out the peaks and troughs, may be counter-productive.
Within a modern office environment, different rooms will require different levels of acoustic performance. Meeting rooms, open plan offices, huddle spaces, contact centre operations and boardrooms will all have different sound profiles.
If you are unsure about the acoustic performance of any space, invest in an acoustic audit. This isn’t as daunting as it may sound (pun intended). An initial audit can be carried out quickly and easily and will provide you with an assessment of the ambient level of noise within an environment (measured in decibels) and the reverberation time (measured in seconds).
Without getting too technical, reverberation time for a room is defined as the time it takes for a sound to decay by 60db from its initial level. For classrooms and offices, a suitable reverberation time would be around 0.5 seconds. If the reverberation time is too high it will result in a perceivable echo.
Stop acoustic issues before they begin
Design your space to keep sound sources and reflections under control or dispersed and add acoustically-absorbent materials to your surfaces to capture reverberations. Look for ways to interrupt or absorb acoustic reflection and isolate sound sources and sound receivers to help stop excessive noise.
As we’ve already seen, it can be easy to overlook acoustics. To help with your next project, we’ve put together a planning guide for designers and architects. This guide is also useful for facilities managers or corporate/commercial organisations looking to ensure an aesthetically pleasing and acoustically healthy environment.
For more information, contact an audio consultant or call us now on +44 (0) 800 319 6094