It is currently accepted that noise is one of the most important annoyance factors in open-space offices. However, noise levels measured in open spaces rarely exceed 65 dB(A). The majority of the 237 respondents consider that the ambient noise level in their environment is high and that intelligible conversations between their colleagues represent the main source of noise annoyance.
Open Offices Lack Privacy & Peace
The modern open-space concept was developed by two German consultants, the brothers Eberhard and Wolfgang Schnelle, in the 1950s. This type of partitionless office layout found considerable success in the USA and has become much more
widespread in Europe since 1980. Most companies have now adopted this type of workspace (according to a survey conducted in 2008, 60% French companies use open-space offices), in all business sectors. There is no specific definition or
size of the open-space office and the layout of these workspaces depends on the individual companies (Bodin Danielsson and Bodin 2008). They may be simple collective offices or completely open platforms accommodating several dozen
employees. The intention of these open-space offices is to improve communication between colleagues and therefore facilitate team or project work, save space and be closer to the managers. Employees nevertheless often complain that they permanently feel spied upon and that they suffer from a high level of ambient noise (noise annoyance related to the work of the other employees and the equipment).
Open Space is Not Recommended
According to one highly exhaustive survey conducted in 2010 by the Haute Ecole de Lucerne on behalf of the Swiss State Secretariat for the Economy (SBiB 2010), noise is one of the main annoyance factors in open spaces. This survey
agrees with several studies which demonstrated that the acoustic environment was considerably less satisfactory in open space offices than in private offices (e.g. Nemecek and Grandjean 1973; Sundstrom et al. 1994; De Croon et al. 2005; Kaarlela-Tuomaala et al. 2009). For example, Kaarlela-Tuomaala et al. (2009) studied employees who moved from a private office to an open space. The study highlights the negative effects of open space on 31 employees interviewed before and after the move. The sound level increased significantly and resulted in more disruptions during work, the feeling of privacy decreased and concentration difficulties increased. This study also demonstrates a lack of the beneficial effects
generally associated with open-space offices: cooperation becomes less pleasant and the circulation of information is unchanged. The researchers conclude that work in open space is not recommended.
Numerous laboratory experiments have demonstrated that noise in offices has a disrupting effect on cognitive performance, such as mental arithmetic (e.g. Banbury and Berry 1998), learning of associated words or a text (e.g.
LeCompte 1994; Banbury and Berry 1998), counting points displayed visually (e.g. Buchner et al. 1998), correction tasks (e.g. Jones, Miles, and Page 1990) and understanding text and recall (e.g. Knez and Hygge 2002; Oswald, Tremblay, and q 2014 Taylor & Francis).
Office Noise Affects Physical & Mental Health
Noise in the work place would also appear to affect physical and mental health. Several researchers (Pejtersen et al. 2006; Haapakangas et al. 2008) have stressed the impact of noise on health by comparing the declared health of people working in an open office and that of people working in a private office. They found that the percentage of occupants complaining about noise was 10 times greater in large open spaces than in private offices. The same study demonstrated an association between office size and several symptoms including headache, fatigue and difficulties in concentration. Open office occupants consider that they need to make significantly more cognitive efforts and have more symptoms related to stress than persons working in private offices. They also feel more tired and more exhausted, though contradictory results
can be found in the literature. As an example, Meijer et al. (2009) noticed no long-term fatigue effects due to open plan office arrangement. But Bodin Danielsson et al. (2014) show, in a recent research, a higher 12-month prevalence of short
sick leave spells among employees in open-plan offices. Marmot et al. (2006) nevertheless observed that persons able to adjust to the environmental factors themselves (light and temperature) suffered less from sick building syndrome than those who are unable to influence their environment.
Currently in France, standard (NF EN ISO 3382-3 2012) specifies the method used to measure the acoustic properties of open-space offices with furniture. This standard takes into account the factors influencing the acoustic performance of open space offices such as furniture layout, acoustic absorption and background noise. It does not take into account, however, how the employees themselves perceive their workplace noise environment, while studies on the assessment of noise in general have demonstrated that the perceived intensity only accounted for 20% (Job 1996) to 25% (Landstro¨m et al. 1995) of the variance in noise annoyance felt by the individuals.
The various studies conducted on the perception of noise in open-space offices emphasize that other factors must be taken into account when assessing the noise annoyance: the noise source(s), the task to be performed, personal sensitivity to noise and the working environment. The effect of these factors is exposed in the later sections.
Source of Office Noise
Removal of partitions in the workspace generates numerous noise sources: phones ringing, people speaking on the telephone, people speaking to each other, computer keyboards, office equipment, musical ambience or background noise, ventilation or air-conditioning system, noise outside the building, etc. (SBiB 2010). It would appear that the noise sources present in open-space offices are not all perceived in the same way and do not have the same impact on the annoyance felt.
Several studies have confirmed in particular that noises considered as controllable and/or useful are less disturbing than noises considered to be uncontrollable and/or unnecessary (Banbury and Berry 2005; Haapakangas et al. 2008; Kaarlela-Tuomaala et al. 2009; Sailer and Hassenzahl 2000; Sundstrom et al. 1994). Similarly, a continuous noise such as that of the ventilation is generally considered as causing little annoyance. It is in fact easier to get used to a constant noise than to a variable noise (Kjellberg et al. 1996). According to these various studies, it seems that the noises considered most annoying and most disturbing for work are telephones ringing (more specifically those ringing in empty offices) and conversations (on the phone or between colleagues). Several studies indicate that the disturbance generated by conversation is largely due to
the quality of speech transmission. Hongisto (2005) puts forward a model describing the disturbance in cognitive tasks according to a speech transmission index (STI). To assess this model, Haka et al. (2009) tested the impact of three STI levels on various cognitive tasks (two verbal recall tasks, one visuospatial memorisation task and two verbal tasks based largely on semantics). This study demonstrated poorer performance between an STI of 0.65 and an STI of 0.10 or 0.35. However, they found no significant difference between 0.35 and 0.10. These results agree with the studies conducted by Jones and Macken (1995) who demonstrated, through several laboratory experiments, that the number of errors in a short memorisation task decreases with the number of voices present during the task, i.e. when the STI decreases. The results are less good in the
presence of one or two voices than in the presence of six voices. The speech level, the content and orientation of the source vary continuously, making it impossible to get used to the speech. Moreover, it has been found that reactions to noise largely depend on the nature of the task to be performed (Beaman 2005).
Office Noise & Type of Task
Kjellberg and Sko¨ldstro¨m (1991) conducted a series of experiments with different more or less simple tasks (a simple and complex reaction time task, a proofreading task and a grammatical reasoning task (GRT)). They reported that the level of annoyance due to noise increases with the difficulty of the task. The disturbance is greater for the GRT than for a reaction time task. Haka et al. (2009) indicate that a visuospatial memorisation task is not disturbed by the presence of speech. Baddeley (2000) explains this result by the fact that auditory information does not interfere with visual information (different coders are used).
Office Noise Sensitivity
Individual factors may also explain the level of noise annoyance. Studies conducted on the annoyance level attributed to noise (Moch and Maramotti 1995) indicate that the sensitivity level estimated by the respondents themselves is related to the perceived annoyance level. The most sensitive subjects claim that they are more exposed than the others and therefore more annoyed. According to a study conducted by Job (1988), noise sensitivity would be highly correlated with the subjective reactions to noise. It would explain approximately 9% of the variance in reaction. In a study conducted in Miedema and Vos (1998), reported that the difference in noise annoyance expressed between persons with low and high sound sensitivity was equal to the difference caused by a variation of 11 dB in the sound exposure.
Perception of Office Noise
Some factors, not necessarily related to the sound aspect of the offices, may also be expressed in terms of perceived noise annoyance. It has been demonstrated that when employees consider that they are working in a satisfactory environment, they tend to attribute this satisfaction to their work, considering that a work situation is satisfactory when the work itself is satisfactory. On the contrary, when the work is considered unsatisfactory, the physical environment is in turn perceived negatively and, in this case, the individuals tend to see it as the source of their dissatisfaction (Fischer 1989). Similarly, it seems important to understand how the physical comfort aspects are assessed by employees (visual comfort, thermal comfort and acoustic comfort) since each one may have an impact on the other. Sundstrom and Sundstrom (1986) demonstrated that the assessment of comfort is subjective and that the assessment of thermal comfort, for example, may be related to other factors such as noise. Haapakangas et al. (2008) also emphasised that persons working in open spaces consider the acoustic quality, as well as the thermal quality, lighting and air quality, of the offices to be significantly lower.
Lee and Brand (2005) studied how the assessment of the working environment and job satisfaction depends on the workspace layout. They measured that the more the respondents claim to be satisfied with their working environment, the
less they perceive distractions. Lee and Brand (2010) also showed that if employees can control their office work environment, the distraction can be reduced. Huang, Robertson, and Chang (2004) demonstrate the importance of the ergonomic aspect in the workplace on improving the efficiency, perceived control and environmental satisfaction. The findings of their study indicate that environmental control is significantly and positively related to environmental
Study: M. Pierrette, E. Parizet, P. Chevret & J. Chatillon (2015) Noise effect on comfort in open-space offices: development of an assessment questionnaire, Ergonomics, 58:1, 96-106, DOI 10.1080/00140139.2014.961972