Abstract
In recent years, it has been increased use of the open plan office in Japan. According to field surveys in Europe and the United States, noise is often the most detrimental factor of the indoor environment in open plan offices. In the workspace with no partitions, group workstations are often directly adjacent. Individuals can be disturbed by the intrusion of unwanted speech from nearby conversations which reduces productivity in the working environment. The purpose of this study was to indicate the acoustic condition both with background noise (air-conditioning noise) and unwanted noise interference from nearby workstations. Subjective judgement tests on desk work and objective measurements were conducted in a simulated office workplace. The results were as follows: The results of subjective judgement tests suggested that the degree of discomfort with hearing unwanted conversation are related to the speech level/background noise level (S/N(A)). However, within the S/N(A) is less than approximately 0 dB, the degree of discomfort with hearing unwanted conversation tend to be strongly affected by background noise. The Articulation Index (AI) is both shown to be well correlated with the degree of discomfort with hearing unwanted conversation and the task disturbance on desk work.
