Noise In Open-plan Offices Research Articles

The effects of moderate heat stress and open-plan office noise distraction on SBS symptoms and on the performance of office work

Three air temperatures (22/26/30 degrees C) and two acoustic conditions-quiet (35 dBA) or open-plan office noise (55 dBA)-were established in an office. Thirty subjects aged 18-29 years (16 male), clothed for thermal neutrality at 22 degrees C, performed simulated office work for 3 h under all six conditions. Many more (68% vs. 4%) were dissatisfied with noise in the noise condition (P < 0.01). Warmth decreased thermal acceptability (P < 0.001) and perceived air quality (P < 0.01) and increased odour intensity (P < 0.05) and stuffiness (P < 0.01). After 2 h, some forehead sweating was observed on 4, 36 and 76% of subjects (P < 0.001) at 22, 26 and 30 degrees C, while 0, 21 and 65% felt "warm" (P < 0.001). Raised temperature increased eye, nose and throat irritation (P < 0.05), headache intensity (P < 0.05), difficulty in thinking clearly (P < 0.01) and concentrating (P < 0.01), and decreased self-estimated performance (P < 0.001). Noise increased fatigue (P < 0.05) and difficulty in concentrating (P < 0.05) but did not interact with thermal effects on subjective perception. In an addition task, noise decreased workrate by 3% (P < 0.05), subjects who felt warm made 56% more errors (P < 0.05) and there was a noise-temperature interaction (P < 0.01): the effect of warmth on errors was less in the noise condition. Typing speed (P < 0.05) and reading speed (P < 0.05) were higher in noise. This paper demonstrates that open office noise distraction, even at the realistic level of 55 dBA, increases fatigue and has many negative effects on the performance of office work, as does a moderately warm air temperature. These findings may be used to provide economic justification for the provision of private offices and air temperature control in hot weather. The additional finding that noise distraction and heat stress can sometimes counteract each other in the short term is of academic interest only, as they both increase subjective distress and fatigue. In practice, neither should be deliberately introduced to counteract the other.

The influence of spatialized background noise on ease of hearing in rooms

The influence of irrelevant noise on worker’s performance has not yet been studied from the standpoint of spatialized background noise in rooms. This paper presents the detriment to Ease of Hearing due to spatial auditory events produced by intruding sound in open plan offices. Auralization is used to represent a generic open plan office noise environment that includes HVAC noise, an intruding voice, and a focus voice. Two different speech communication environments are presented to the listener. In the first presentation, the intruding voice is located far from the listener’s workstation (in the reverberant field) and is not localizable. In the second presentation, the intruding voice is localized near the listener’s workstation. The focus voice is localized in front of the listener for both presentations. These sounds are played over a five-channel auralization system. Listeners are tested for the degree of Ease of Hearing (EOH) of the focus voice. Psycho-acoustical test results are presented to show the difference between the Ease of Hearing in each case. Improvement strategies to keep high quality communication are also presented based on the results.

Ambient noise in open plan offices

This paper summarizes ambient noise data that were collected in open plan offices over the past 2 years. The approach centered on monitoring the noise level in empty workstations to establish some statistics of the noise that would be auditioned by a person sitting in that workstation during a normal work day. Offices both with and without electronic sound masking were investigated, as were offices with either acoustically hard or acoustically soft screens. It was found that the noise level in an individual workstation increases with the number of people in this office. For the 25 workstations considered in this investigation, the average daily noise level in a workstation ranged from 42.2–58.6 dBA. The noisier workstations usually had both (i) electronic sound masking and (ii) acoustically hard screens, whereas the opposite was usually found for the quieter workstations.

How to cope with noise in open plan offices

The shape of the rooms, the behaviour of the ceiling to the angle of sound, the number of people accommodated in a given space—all these factors are discussed by the author in relation to measurements taken in offices in Europe and Scandinavia. The generic term ‘open-plan’ is used to describe the offices, since not everyone agrees on what consititutes a truly landscaped office. The author is a consultant with the Acoustic Advice Bureau, IR.VMA Peutz BV, of the Netherlands.