How to Achieve Great Acoustics in the Workplace
Improved acoustics in the workplace environment = improved productivity and staff well-being.
Sound can affect our ability to concentrate and a noisy working environment can have an adverse effect on our ability to work effectively.
While many people are aware of the problems created by poor acoustics, often there is confusion about what solutions are most effective at solving these problems. To understand how the solutions work, first you need to understand how sound travels.
How do we hear sound?
Vibrations in the air, caused by vibrations of objects, travel to our ears. They cause the the eardrum to vibrate and this is passed to the very small bones in the inner ear. Messages are sent to the brain and interpreted as sounds.
The ear is specially tuned to receive sounds. Vibrations in the air are not always the same – and the speed at which the air particles move tells us the frequency of vibration. The way we perceive the change of vibration speed is as a change of pitch. The pitch of a sound describes how high or low the sound is. For example, a whistle has a high pitch, a bass guitar has a low pitch.
How sound travels
Imagine dropping a stone into still water. What happens? Ripples spread out in ever-widening circles. When the ripples reach the side they are reflected back.
Sound travels in the same way. When sound energy comes into contact with a surface, it is reflected back. The harder and denser the surface, the more sound is reflected back, so a room with a hard floor and walls creates more noise. When a surface is soft (and therefore more sound absorbent) some sound energy is lost.
Absorbing materials prevent sound reflection.
Sound travels through – or is ‘transmitted’through – doors or walls.
Blocking materials prevent sound transmission.
Speech privacy and speech intelligibility
In the workplace environment, speech privacy is essential, but in many open plan offices, speech is often the loudest source of sound.
Speech intelligibility describes how clearly speech can be heard and understood.
Speech privacy describes the degree to which a conversation can be held without the words being audible and clearly understood.
To have speech privacy you must decrease speech intelligibility.
How can this be achieved? By covering sound.
We can cover sound with ambient noise.
This is background noise. It can include traffic noise, or the sound of air-conditioning. It is a non-threatening noise which we can ‘tune out’ and it is useful because it may make a distracting noise less noticeable and it can increase speech privacy between two areas – speech may still be slightly audible but not as intelligible.
So, solving acoustic problems in the workplace is a simple as A,B, C – ABSORB, BLOCK, COVER
Absorbers correct the reverberation or reflection of sound in a room.
Blockers interrupt the sound path and act as a barrier.
Covers provide a ‘mask’ by artificially increasing the ambient or background noise, thereby aiding speech privacy.
Good acoustic design will create different areas or zones for different types of work, each having a different acoustic requirement.