Application of the combined effect of environmental variables on the human responses to soundscape design for universal comfort

The purpose of this study is to clarify what sound is pleasant in human environment and what circumstance is pleasant for the humans. Twenty-one male students were exposed to the 32 combined conditions of temperature levels (19, 24°C(SET*)), illuminance levels (5, 530lux) and environmental sound sources (airconditioning noise, “wind-bell”, “insects in autumn”, “wavelet on sandy beach”, “train”, “chirping birds”, “robust cicada”, “heavy rain”). The subjects reported the impression and sensation of the exposed environment on the ballot after presenting the sound stimuli every 150 seconds during 60 seconds exposure. The results showed that natural sounds of chirping birds, insects in autumn and wavelet on sandy beach improved the uncomfortable evaluation in 19°C-5lux condition. However, the same stimuli were found not always to have the similar effect on neutral feelings resulting from another thermal and lighting conditions. It is concluded that the soundscape design is only effective in improving environmental assessment under moderate uncomfortable conditions. (Archives of Complex Environmental Studies (ACES) 14(3-4) 2002)