Although numerous critics have discussed the impressionist aspects of The Secret Agent, they have focused primarily on the novel's visual imagery and given little attention to Joseph Conrad's extensive descriptions of sound. Both painters and musical composers influenced literary impressionism, however, and Conrad uses aural imagery in the novel both thematically and descriptively. For a novel about secrecy — secret agents, secret meetings, secret feelings — silence is essential. Thus, sound functions as a disruptive force, indicating the revelation of destructive secrets. Conrad's sound imagery also fulfills his desire to make readers "hear" through the written word and to evoke the suggestive power of music. This article analyzes Conrad's aural descriptions in The Secret Agent in an attempt to broaden the critical understanding of the author's impressionist techniques.