Abstract
Experiments were conducted to evaluate the economic value of the sound quality of machinery noise emitted from vacuum cleaners and hair dryers. In the experiment concerning vacuum cleaners, stimulus cards of twenty-seven kinds of vacuum cleaners were presented to participants. Each card gave participants details of the characteristics of each vacuum cleaner in respect to six attributes; manufacturer, price, noise level (dBA) and sharpness (acum) of the machinery noise, etc. Each attribute had two to five levels. For the attributes of noise level and sharpness, three levels were set up (64, 59, 54 dBA and 2.46, 2.21, 1.96 acum, respectively). 50 students evaluated their preferences for each vacuum cleaner. Rating values were applied to conjoint analysis. As a result, students regarded "price" as most important. The partial utilities of each level for each attribute were also obtained. In the attributes of noise level and sharpness of the machinery noise, the partial utilities increased as noise level and sharpness decreased. Furthermore, the estimated value for a 5 dBA reduction was 3347 Japanese yen, and for a 0.25 acum reduction, approximately 3692 Japanese yen.
