What Is Workplace Acoustics?

Nowadays, workplaces are dramatically different, but acoustics remain a leading concern among office workers. To discuss why this is, it’s helpful to understand a few terms first.

workplace acoustics

Acoustics The scientific discipline associated with the study and treatment of sound.

Sound. A vibration or waveform that stimulates a receptor (i.e. one’s ear). Our ability to hear sounds varies greatly across the population and the same individuals across time.

Noise. Unwanted sound. Noise is perceived as requiring mental processing and interpretation.

Privacy. Also a perception, privacy is time, place, individual, and situation-specific. Privacy cannot be easily (if ever) quantified, but it can be qualified. Control over when and how distractions occur contributes to an increased sense of privacy.

Distraction. Something causing a loss of attention or focus. Distractions are usually acoustic or visual. At work, distractions can interrupt workflow, causing performance to suffer. But not all distractions are bad. For example, overhearing co-workers may be critical to successful project completion. Also, not all noise is equally distracting. Three key elements of a sound contribute to distraction:

The relative loudness. For example, a cough or sneeze in a library is more distracting than a shout at a sporting event. A dog barking in the middle of the night appears much louder than when barking as children come home from school.

The intelligibility. Our attention is drawn to familiar sounds. Hearing our name from across a room is much more distracting than louder, less intelligible sounds.

The characteristic. Irregular sounds tend to be more distracting than regular or rhythmic sounds. Some frequencies are more distracting (e.g., high-pitched squeals, versus low-pitched hums). Also, hard, percussive

sounds or slammed doors are more distracting than softer sounds or letter combinations. Several recent facilities management (FM) trends have exacerbated the problem of workplace noise:

Smaller individual workspaces.

Increased density. Alternative office strategies (like hotelling and hot desking) coupled with smaller spaces and less circulation space have led to greater numbers of people per square foot in most offices. More open workspaces. Fewer enclosed spaces, lower partitions, and more open spaces.

Consequently, today’s workplace is noisier than ever. Why should facility managers (fms) care? Two simple reasons:

Noise affects behavior. People become irritable. Long-term exposure, especially to loud sounds, causes hearing and overall health to suffer.

Distractions and interruptions affect worker performance. The greatest affect on performance and job satisfaction is the ability to do distraction free work—and noise is the greatest distraction. Interruptions occur, on

average, every eight to 10 minutes. Recovery times from interruption or distraction average seven to 15 minutes.

So what can be done? Most acoustic solutions use an ABC approach:

Absorb. The simplest way to control noise is to use good absorptive materials in ceilings and floors. Unfortunately, many offices are finished with non-absorptive flooring and mineral fiber ceiling tiles. Some tiles may look acoustic but are actually very reflective. Truly absorptive ceiling and flooring materials can be costlier but are extremely effective in dampening unwanted noise thereby leveraging the higher cost by improving performance.

High Ceilings and Open Layouts

Block. Walls can block sound, but walls and partitions are less effective in controlling noise than absorptive ceilings and floors. Unless partitions use absorptive materials, they cause more problems than they solve by reflecting sound. To be truly effective, acoustic barriers walls need to pierce the ceiling and plenum area to the deck of the floor above. This becomes impractical since most office workplaces need to accommodate reconfiguration. Moveable partitions facilitate reconfiguration but stop at the suspended ceiling, offering limited, but not ideal sound blocking.

Furniture panels and cubicle walls made of absorptive materials claim to be effective noise barriers. Furniture panels are assigned Noise Reduction Coefficients (NRC). This is an artificial measure collected in anechoic chamber bearing little resemblance to an actual workplace. Measuring NRC addresses only one of the four possible paths noise can take. In real offices, noise flows over and around partitions and bounces off people and surfaces. At best, furniture is only marginally useful in absorbing or blocking sound. Partial height partitions may actually contribute to noise by reflecting or diffracting sound. Also, partial enclosure gives the illusion of privacy, encouraging people to act as if unseen means unheard.

Cover. Sound masking (and more recently “scrambling”) is commonly used in open office environments to cover noise. But effective sound masking requires significant expertise and planning. Sound masking adds sound to dampen the intelligibility of certain sounds by raising the overall ambient sound level. This is like spraying a fragrance to cover an odour; often the results (if not done properly) can be more annoying than the original problem.

If controlling noise in workplaces is as simple as ABC, why is noise still a problem? Why do so many people complain, use headphones or hide in conference rooms to get their work done?

workplace acoustics

Two reasons. First, the ABC approach assumes noise is strictly an environmental problem that can be solved with materials and technology. It ignores the fact that people are the source of most office noise. The most effective way to deal with office noise is by changing behaviour. Coaching people to use “inside voices” and to be aware of when they may be distracting or disturbing others must accompany appropriate environmental changes.

Second, distance. The distance between source and receptor is critical in controlling noise. Permanently increasing distance between people is difficult and generally not practical in today’s economic climate. But distance can be increased as needed by providing appropriate zones and shared spaces for noisier activities like conference calls and collaboration. Encouraging people to move away from others when engaging in noisy activities temporarily increases the distance between source and receptor.

So, the ABC of noise control should be changed to ABCCD.

Any discussion of increasing real estate costs, expanding workspace or spending more up front to address noise is heresy these days. But the opportunity for FM to have a positive impact is undeniable. The equation is simple and persuasive: reduced space = lower CRE costs = increased density = more noise = lower performance = falling profits.

For all of your workplace acoustics and soundproofing needs, contact Acoustica Projects now.

Call us 1300 498 268

Email us – enquires@acousticaprojects.com.au

Website –  https://www.#.com