The development of the anthropomorphic flutist robot, at Waseda University, has demonstrated how the robot can communicate with humans at emotional level by performing musical scores with expressiveness and by transferring basic skills from robot to beginners. However, the interaction among humans is characterized by a highly interactive process of analyzing and responding to incoming stimuli from the partner. Even that flutist robot has successfully imitated the flute playing quite similar to human performance; the way of processing and analyzing the music as human does still requires further improvements. In this paper, we will describe how we implemented a human like sound processing system to enable robot to interact with humans at the same level of perception. An experimental setup was done to verify the validity of the developed system.