Office design: Good acoustic design reduces unwanted sound
Noise can be defined as any sound you don’t want to hear. Within the office environment the noise generators are people and equipment. Its effect on office workers can be significant with increased levels of stress, lower productivity, fatigue and lower staff morale. More specifically, tasks requiring high levels of cognitive skills such as reasoning, numeric processing, sustained attention, etc. become much more difficult to complete accurately as noise levels rise. In other words, poor acoustic design can have a substantial effect on the overall commercial performance of a business.
To minimise the effects of noise, progressive office designers are working closely with acoustic specialists to identify the sources of noise and then devise strategies to reduce or eliminate them.
No matter what the source of the noise is, there are basically only three recognised acoustic strategies to control it – by Absorption, by Blocking and by Covering (masking). In the world of acoustics this is known as the ABC.
Absorption techniques involve covering floors, ceilings and walls with sound absorbing materials. Carpet is a very effective sound absorber. Specialist sound absorbing ceiling tiles such as Armstrong’s Ultima create a very effective sound absorbing surface. Sontext produce a wide range of fabric covered panels and perforated timber panels as sound absorbers.
Blocking techniques work by blocking the direct sound path between the noise source and the noise receiver. Good acoustic practice is to ensure that there is not a direct line of sight between the source and the receiver. The most common and effective solution for blocking noise are solid internal walls. However, in an open plan office the individual workstation screens made from sound absorbing material can also play a significant role in blocking noise. Of course, there will still be noise which goes around the sides and over the tops of the screens, but a screen with a minimum height of 1350mm will significantly improve the acoustics in the space. Interestingly, if the screen height is too high, creating a ‘private’ space, noise can significantly increase, as people assume they can talk louder.
Masking techniques work by using a generated background sound, delivered through a series of above-ceiling speakers. The generated sound will cover any sound below the level of the background sound and at the same time lessens the impact of the sounds above the level of the background sound. These systems are now very sophisticated and are light years away from the original ‘white’ noise generators
A fourth and often overlooked way to control noise is through behavioural protocols. Many organisations develop and enforce strict workplace rules for noise control to cover such things as speech levels, use of speaker phones, ringtones, personal music and impromptu meeting zones outside designated areas. By actively applying a sensible set of protocols, noise levels in any space can be significantly reduced.
Without doubt, the ’open plan’ office design highlighted and exacerbated the effect of noise on health and productivity. As ‘open plan’ designs develop into ‘activity based’ workplaces there is a need for much more emphasis on acoustic controls. Each activity ‘zone’ will need to have its own set of controls. For example, a quiet zone will have a different acoustic solution to that of a private meeting room or a team work area. In other words, the whole range of blocking, absorbing and masking acoustic techniques may have to be applied to each ‘zone’
Looking into the future, it is perfectly conceivable that it may be possible for the individual to select their own acoustic conditions for the space. For example, masking sounds could be varied or workstation acoustic screen heights raised to alter the acoustic profile. Perhaps even further in the future, dynamic systems that sense the user’s behaviour and then adjust the acoustic profile accordingly, may be the ultimate solution for ‘noise’ in the office.
In summary, the top tips to win the noise war in the office:
- Noise affects health and productivity, so don’t ignore it – it doesn’t go away.
- Understand the principles of acoustics or if not, design spaces with an acoustic specialist beside you.
- Acoustic design, like interior design, is a series of compromises, largely determined by the physical constraints of the space.
- One acoustic solution does not fit all – use a combination of acoustic techniques to produce the optimum solution.
If you would like to read more about the effect of open-plan layout on employee productivity, you may enjoy some of our other articles on this subject “Office design: even tiny changes can boost workplace well being” or “Office design: the real story behind “collaborative” workplaces”
The articles on the Charter Build blog – Officeionado – are written by the CB team and edited by Jane Bright, our Design Director. If you have any questions regarding our content, syndication of our content or content submissions, please contact Jane via email firstname.lastname@example.org. For notification on new blog posts either subscribe (top of sidebar on this page) or follow Charter Build @charterbuild and Jane Bright @1JaneBright.