The conventional method for noise control attempts to simply reduce the level of product noise. The principles of noise control normally have to do with identification of noise sources, their relative importance, and evaluation of possible noise control procedures as they apply to source, path, and receiver. These have been common practice in noise control industry. This does not consider the actual feeling of consumers on a product sound.
In this study, we propose a method of noise control, which takes into account the subjective perception on product sound. In addition we investigate a possibility to apply the proposed method. As a practical example of the presented study, the sound measured from a refrigerator is investigated. The proposed method is composed ,of 4 steps. Firstly, a refrigerator noise signal is measured. Then, a sample noise set is prepared for subjective assessment. They are edited in frequency domain. In order to interpret subjective feeling of the sample noise set, a listening test is required. For the test, subjective rating method and relative comparison method are used. For a statistical analysis of the listening tests, analysis of variance (ANOVA) and paired comparison method are used. Finally, we establish a strategy of refrigerator noise control by using those results from subjective assessment of the sample noise set. To verify the subjective assessment results, the sample noise set is also analyzed with respect to sound quality metrics such as loudness, sharpness, roughness and fluctuation strength.
