Hierarchical filtering method for content-based music retrieval via acoustic input

This paper presents an implementation of a content-based music retrieval system that can take a user's acoustic input (8-second clip of singing or humming) via a microphone and then retrieve the intended song from a database containing over 3000 candidate songs. The system, known as Super MBox, demonstrates the feasibility of real-time music retrieval with a high success rate. Super MBox first takes the user's acoustic input from a microphone and converts it into a pitch vector. Then a hierarchical filtering method (HFM) is used to first filter out 80% unlikely candidates and then compare the query input with the remaining 20% candidates in a detailed manner. The output of Super MBox is a ranked song list according to the computed similarity scores. A brief mathematical analysis of the two-step HFM is given in the paper to explain how to derive the optimum parameters of the comparison engine. The proposed HFM and its analysis framework can be directly applied to other multimedia information retrieval systems. We have tested Super MBox extensively and found the top-20 success rate is over 85%, based on a dataset of about singing/humming 2000 clips from people with mediocre singing skills. Our studies demonstrate the feasibility of using Super MBox as a prototype for music search engines over the Internet and/or query engines in digital music libraries.