Acoustic Privacy – Overcoming the invisible invader
Acoustic privacy considerations for open plan offices
Sound is invisible; do we need to worry about it? If it was water leaking into a space rather than distracting sound, the problem would be fixed immediately! Sound can ‘leak’ into spaces and create just as much damage to workplace performance, but we are expected to ignore it much more willingly. We compromise acoustic disruption at the expense of worker effectiveness. Because sound is invisible, we tend to underestimate its importance.
Good acoustic performance is a key contributor to worker effectiveness and culture management in the workplace. We all need times of quiet and places to support complex knowledge work. On other occasions it’s necessary to have planned or spontaneous interactions without disturbing others for team work and relationship development. Speech privacy also is essential for confidential interactions and work processes.
Today’s work thrives on interaction and communication. The biggest distractions in office noise come from people talking. The noise follows pathways; through ceilings, through walls, through air conditioning vents and lights; this enables sounds to be heard by others in nearby rooms and spaces. Acoustics is the art of identifying, understanding and controlling the transmission of noise. The energy of sound filters through every opening no matter how small; just like water from a bucket with holes.
People get phone calls they must deal with; a quick conversation with a colleague to move a task forward; a conversation with others nearby for both social and work reasons. Creating distance is difficult. With open plan offices becoming more popular, people are now 2 – 3 metres apart at their desks and constantly creating noise. Employees clearly value the opportunity to communicate more effectively therefore it is paramount to ensure that office workers will have the privacy and acoustical comfort they need to be effective.
But why should we care so much about distractions? Distractions and interruptions have serious consequences on an employee’s ability to work effectively; they are not just a source of annoyance and acoustic dissatisfaction:
Shifts in attention that reduces focus;
increased efforts to concentrate, which can increase stress levels and fatigue;
Abandoning a current task to deal with demands caused by an interruption;
Losing flow of thought and the need to re-orient to the task, which can take up to 15 minutes
It is imperative to achieve an appropriate acoustical comfort balance for interaction, confidentiality, and concentrative work
Even though good acoustics is a key contributor to interior quality, it is often an afterthought rather than an integral component of the contemporary workplace. Acoustic quality is even more critical today with the current design trend to eliminate unused space and achieve sustainability goals in new and renovated buildings. Reduction in space will lead to more intensely used workspace which may exacerbate current acoustic problems. In addition, sustainable design requires attention to materials used in furnishings and construction. Materials that achieve sustainability goals may not be the best choice for acoustic comfort. Goals to decrease energy use by enhancing daylight penetration can also inadvertently create acoustic problems associated with lower workstation panels which offer fewer opportunities for sound absorption and more glass surfaces which are hard and not acoustic absorbing.
Appropriate design needs to take into consideration room configuration, and selection of surface materials, including ceiling, wall, flooring and window treatments. Consequently, it is essential to properly separate areas designed for speech intelligibility from those that require speech privacy.
Large spaces, such as lobbies, reception, and cafeterias, are often noisy spaces that should be acoustically isolated from adjoining open workspaces. Acoustical separation should also occur between high traffic corridors or circulation pathways and adjoining open work areas.
Successful acoustic strategies rely on three techniques which can be applied in a wide variety of ways: absorb sound, block sound transmission from one space to other spaces, and cover through sound masking. While the following treatments are minimum approaches for achieving acoustical comfort and speech privacy, resist bartering away acoustic mitigation during any subsequent “value engineering” for the good of the work and the employees. Remember, acoustics under-performance is the greatest source of user dissatisfaction.
Open workspaces require acoustical treatment on a significant portion of the surfaces in the space to absorb noise from people and equipment – floors, walls, window coverings, and ceilings can all be used to absorb sound. Specific solutions include acoustic ceiling panels, hanging ‘clouds’, carpeting, furniture finishes, curtains, and wall treatments such as acoustic panels and fabrics. The more absorptive the material added to the open space and the higher the acoustical performance rating of the material, the more acoustically comfortable the environment is likely to be. Two surfaces are key contributors to absorption: high quality acoustic ceiling materials are typically the most significant contributor to sound absorption. Similarly, walls may be treated with acoustic material, either applied to a surface or integral with the wall finish. In addition, floors are an important source of absorption, especially to dampen footfalls. For instance, carpet is especially effective at absorbing the irritating sound of footfalls, but cork and linoleum or other absorptive materials also work; whereas marble or ceramic tile will have the opposite effect.
Two key points to remember when specifying acoustics:
Personnel costs far exceed the cost of this mitigation!
Building acoustic comfort into your new project comes at a significantly lower cost than attempting to eliminate the grievances later!
Sound Masking Systems are another effective alternative, particularly in open plan office areas. Another augmentary approach is to increase the background noise in the space. Though this seems counter-intuitive, a low level of background noise allows interruptions to contrast with the quiet, causing a greater distraction than if the space had a higher level of background noise. A sound masking system creates a low-level of continuous and unobtrusive background sound that is essential for acoustical comfort and speech privacy, sometimes referred to as a ‘white noise’.
Having doors on rooms is just as important for good acoustics, as is the design of the doors themselves. Whether it is a sliding door, a hinged door or a pivot door, they all impact the acoustic stability of the environment differently depending on how sound can escape through or around the door.
Plan to enable speech intelligibility where it is required most, from team meetings in small conference rooms to all-hands meetings or huddles in shared open spaces and, most typically, in formal conference rooms.
Atkar has been achieving excellence in acoustics for over 40 years. Working directly with the design and construction industry, our role is to help transform design potential into successful, built solutions; assisting each customer in achieving their expectations and much more.