Sound quality gains importance in our daily life. One of the important household appliances which has a long operational duration is washing machine. The washing machine sounds have mostly instationary character. Two main operational stages, which are washing and spin, cause totally different sounds. Although, the sound of the washing part is relatively quiet, machines emits very loud sounds during the spin cycle. In this study, we concentrated on front-loading washing machines. The aims of this study are to evaluate the perceived overall quality of various washing machine sounds and to identify the perceptually important features of the washing machine sound which are relevant to the quality impression. To systematically approach to these aims, first the washing machine sounds were recorded and the recorded stimuli were modified via digital filtering in frequency and time domains. Then the recorded signals were analyzed and their psychoacoustical metrics were calculated, in parallel a listening test to evaluate the sound quality was conducted. The results of the psychoacoustic analyses and the jury test were correlated and a sound quality index was developed.