Open plan office acoustics – a multidimensional optimization problem
* Presenting author
The international standard ISO 3382-3:2012 defines a number of measurable room acoustic parameters for the objective evaluation of the acoustics of open plan offices. The main acoustical problem is distraction by speech and conversation between other people. However, this is not a simple one-dimensional noise problem that can be solved by a sufficiently high damping of the room. If the reverberation time is very short, the remote voices are heard with high clarity and thus the amount of distraction is high. But a long reverberation time leads to a very noisy environment, which is also disturbing. Similarly with the background noise: It should be neither too low nor too high. The most interesting acoustic parameters are the distraction distance and the privacy distance, both derived from the Speech Transmission Index (STI). These parameters depend on the important acoustic parameters, namely the amount of absorption, the effect of screens, the spatial attenuation and the masking from background noise. For the acoustical design, it is suggested to take the background noise from human activity into account, assuming a vocal activity that depends on the type of office. A sufficient volume per person seems to be an important design parameter.