A domineering money-bags' suppressed incestuous urges go into overdrive when her half-brother brings a new bride home to the family’s gloomy Fifth Avenue mansion. The title refers to a secret soundproofed chamber that the villainess uses to entrap her enemies.
| Directing | Charles Vidor | Director |
| Writing | Jack Cunningham | Screenplay |
| Writing | Gladys Lehman | Screenplay |
| Production | E. Lloyd Sheldon | Producer |
| Editing | James Smith | Editor |
| Writing | Elizabeth A. McFadden | Theatre Play |
| Camera | Fred Mayer | Camera Operator |
| Writing | Elizabeth A. McFadden | Writer |
| Art | Hans Dreier | Art Direction |
| Art | Robert Odell | Art Direction |
| Camera | Harry Fischbeck | Director of Photography |
