Effect of sound masking on workers in an open office Free

Appropriate masking sound is necessary for reaching acceptable speech privacy in open offices. However, the electronic masking systems have not become very popular although the importance of masking is emphasized in design guidelines worldwide. One reason may be that very few scientific field experiments have been published in this area. The aim of this pilot study was to investigate the effects of artificial masking sound on workers in a small department of 15 workers. Measurements and questionnaires were conducted before and after launching the system. Masking sound 44 dBA was produced using centralized pink noise generator and ceiling loudspeakers. The spectrum reminded ventilation noise. Initial background noise level was 36 dBA. Acoustic measurements showed that masking sound reduced the radius of distraction rD from 15 m to 7 m, i.e. acoustic privacy improved significantly. The questionnaire revealed several positive changes attributable to masking. Distraction caused by speech and other varying office sounds was reduced. Noise‐related stress was reduced. Evaluations of acoustic environment, speech privacy and self‐rated work efficiency were improved. The results showed no adverse effects of masking on workers.