Oh J., Park S., Kim H., Sim H., Lee J.

Since human listening is very sensitive when the sound hit him, the subjective index of sound quality is required. Therefore, at each situation of sound evaluation it is composed with the Sound Quality (SQ) metrics. But, when substituting the level of one frequency band we could not see the tendency of substitution at whole frequency band during the SQ evaluation. In this study a Design of Experiments (DOE) is used for noise from an automotive Heating, Ventilating, and Air Conditioning (HVAC). The frequency domain is divided into an equally 12 parts and each level of domain whether is given increase or decrease due to the change of frequency band based on ¡®loud¡¯ and ¡®sharp¡¯ of the SQ is analyzed. By using the DOE the number of test is reduced very effectively by the number of experiment and each band the main effect will be as a solution. The case of SQ for ¡®loud¡¯ and ¡®sharp¡¯ at each band, the change of band (increase or decrease of sound pressure or keep maintain) which will be the most effect on the characteristics of SQ can be identify and this will be able to us to select the objective frequency band. Through these obtained results the physical changes of level at arbitrary frequency domain sensitivity can be adapted.