Distraction distance and perceived disturbance by noise—An analysis of 21 open-plan offices

Abstract

Previous research suggests that, in open-plan offices, noise complaints may be related to the high intelligibility of speech. Distraction distance, which is based on the Speech Transmission Index, can be used to objectively describe the acoustic quality of open-plan offices. However, the relation between distraction distance and perceived noise disturbance has not been established in field studies. The aim of this study was to synthesize evidence from separate studies covering 21 workplaces (N = 883 respondents) and a wide range of room acoustic conditions. The data included both questionnaire surveys and room acoustic measurements [ISO 3382-3 (2012) (International Organization for Standardization, Geneva, Switzerland]. Distraction distance, the spatial decay rate of speech, speech level at 4 m from the speaker, and the average background noise level were examined as possible predictors of perceived noise disturbance. The data were analyzed with individual participant data meta-analysis. The results show that distracting background speech largely explains the overall perception of noise. An increase in distraction distance predicts an increase in disturbance by noise, whereas the other quantities may not alone be associated with noise disturbance. The results support the role of room acoustic design, i.e., the simultaneous use of absorption, blocking, and masking in the attainment of good working conditions in open-plan offices.

Perception of Water-Based Masking Sounds—Long-Term Experiment in an Open-Plan Office

“…Further research in this field is important because a recent field study showed that noise disturbance is higher in offices where the distraction distance is large (Haapakangas et al, 2017). It was also found that the background noise level of the office (noise level of masking and ventilation) was associated with noise disturbance: the lower the background noise level was, the higher was the perceived noise disturbance.…”

“…A recent study including 21 offices provides evidence that noise disturbance is lower in offices where the distraction distance is smaller (Haapakangas et al, 2017). Distraction distance is an objective single-number quantity which describes the room acoustic quality of an open-plan office.…”

“…Based on abovementioned references, it is relatively easy to conclude and demonstrate that the increment of sound masking level is the easiest way of reducing the STI . Furthermore, Haapakangas et al (2017) found that noise disturbance was lower in offices where the background noise level was higher. Their study involved background noise levels between 29 and 45 dB L Aeq , where L Aeq is the A-weighted equivalent sound pressure level.…”

Benefits of quiet workspaces in open-plan offices – Evidence from two office relocations

“…Table 5 shows the main outcomes, which are the distraction distance rD, the spatial decay rate of A-weighted speech level D2,S[dB], the A-weighted level of speech at a 4-meter distance LA,S,4m [dB] and the background noise level caused by building services, LA,B. The rD is the most essential for the perception of noise (Haapakangas et al, 2017). The rD describes how far from a single speaker the speech is distracting.…”

“…Therefore, defining a space as an open-plan office is not sufficient for predicting its effects on workers. For example, the perception of office noise depends on room acoustic details which vary greatly between workplaces (e.g., Haapakangas, Hongisto, Eerola, & Kuusisto, 2017;Seddigh, Berntson, Jönsson, Danielson, & Westerlund, 2015), demonstrating the need to investigate the role of specific features within the broad category of open-plan offices.…”