Human considerations should guide good acoustics

How serious a problem is poor sound quality in offices?

From surveys, we know that noise is always one of the three most annoying factors in open plan offices. Over the years, this seems to be the same conclusion in this type of investigation.

From an acoustic perspective, what are the most important things to consider when planning new office space?

The options for acoustics design are not affected much by the number of employees but more by the kind of tasks performed in the room.

For example, a call center with a lot of phone communication is different from an office where the employees mainly perform quiet work. The ratio between concentration versus communication in the work tasks defines the acoustic requirements. This human consideration should be the guideline for the acoustician, not just the materials, surfaces and technical features of the room.

If an existing office has poor acoustics, what measures might be taken to improve the sound quality?

To get an objective description of what "poor acoustics" means, we usually suggest measuring the acoustic performance of the room, such as reverberation time, speech intelligibility and other factors. From this assessment we can, with the help of a room model, precisely predict what measures will be needed to achieve the optimum acoustic quality in the room.

The choice of surface materials is also important but many factors influence this decision. Many people focus only on selecting highly absorptive materials but where they are placed and the size of the covered area matter as well. For instance, it might be a better choice to cover an entire wall or ceiling with a material that only absorbs 50 percent of the sound, rather than covering only half of the surface with a highly absorptive material.

What can be done to take into consideration the special needs for sound quality in certain types of rooms, such as call centers and meeting rooms?

Meeting rooms are quite different to call centers, just like an opera house is quite different to a theatre for plays.

In a meeting room, the solution will focus on good speech intelligibility over both short and long distances between the speakers and the listeners.  However, in a call center there is a need to dampen noise and intelligibility over short distances. So, acoustically, these types of rooms are very different and require different solutions.

Are there new trends that will affect the acoustic needs of office design in the future?

Some of the new trends such, as green building design or the popularity of glass, affect acoustics in general. In other words, while the acoustic requirements for offices stay the same , the materials and techniques used to achieve good acoustics need to be adapted.

Also today there is a lot more communication technology in many offices. This needs to be taken into account when planning for optimum office acoustics.

About Dr. Christain Nocke

• Expert on noise emission and architectural and room acoustics

• Founded Aukstikbüro Oldenburg in 2000

• Former director of Geschäftsstelle der Deutschen Gesellschaft für Akustik e.V.

• Author of the book ‘Raumakustik im Alltag – Hören - Planen – Verstehen’, Fraunhofer IRB Verlag.