Comparison of Response Scales as Measures of Indoor Environmental Perception in Combined Thermal and Acoustic Conditions

Response scales are widely used to assess the personal experience of sensation and perception in built environments, and have a great impact on the quality of the responses. The purpose of this study was to investigate the effects of response scales on human sensation and perception in moderate indoor environments. Four different response scales were compared under three room temperatures (19.0 degrees C, 24.5 degrees C, and 30.0 degrees C) and five acoustic stimuli (ambient noise, 42 and 61 dBA x water sounds and traffic noise): a bipolar seven-point scale according to ISO 10551:1995, a unipolar 11-point scale according to ISO/TS 15666:2003, these two scales combined for each sensory comfort assessment, and a bipolar visual analogue scale. The degree of relative differentiation based on indoor physical factors made no significant difference across the four response scales. Therefore, the effects of physical factors on human response could be assessed by using any of the four scales tested in this study, with a statistical significance at p < 0.05 in moderate environments. The choice of response scale would depend not only on the type of physical stimulus but also on the question of sensation or perception. The reliability of each response scale was different according to the subjective attributes. The bipolar visual analogue scale was subjectively preferred by the respondents.