Traditional audio retrieval systems deal principally with audio clips having text descriptions. To retrieve unannotated audio clips is cumbersome because of the immaturity of content-based analysis and retrieval techniques. In this paper, we propose a two-stage audio retrieval method, consisting of a first stage of text-based retrieval and a second stage of content-based retrieval. This new retrieval method can be employed to retrieve audio clips from an audio collection having only partial text annotations, which is true of many online audio datasets. We have developed a prototype audio retrieval system based on our algorithm and carefully evaluated its performance. The results demonstrate the effectiveness of our new audio retrieval method. Our method can be generalized and applied to other kinds of non-textual data such as images and videos.