Audio Watermarking of Binaural Room Impulse Responses

Digital audio watermarking is an extensive research area, currently with a strong focus on improving established watermarking schemes for conventional audio content. At the same time, headphone-based virtual acoustics, as part of virtual or augmented reality (VR / AR) technologies, takes on greater significance, and therefore methods are needed to protect the copyright of binaural room impulse responses (BRIRs). To approach this subject, we developed a novel perceptual-based algorithm for watermarking impulse responses. To our knowledge, this is the first study investigating audio watermarking schemes for BRIRs. In a listening experiment, watermark detection thresholds in dynamic binaural synthesis were determined for two rooms and two test signals. A subsequent technical evaluation focused on the robustness against common watermarking attacks. The analysis showed a clear influence of test signal and room on perceptibility and robustness of the watermark. Overall, the results suggest good perceptual transparency and robustness of the proposed method in a reasonable watermark-level range.