# Binaural Rendering with Measured Room Responses: First-Order Ambisonic Microphone vs. Dummy Head
## 4 Conclusions  
We evaluated two fundamentally different measurement-based binaural audio rendering strategies in a novel comparative listening experiment: The dummy-head-based strategy employs binaural impulse responses measured in multiple orientations (MOBRIRs) and hereby contains the required set of binaural cues of the dummy head for dynamic (head-tracked) rendering. The Ambisonics-based strategy uses the room impulse response measured by a first-order Ambisonic microphone (ARIR) in a single orientation, which is upscaled from its weak directional resolution to higher orders using the Ambisonic spatial decomposition method (ASDM). Dynamic binaural rendering is then accomplished separately through an Ambisonic rotator and binaural renderer.  
Our experiment successfully compared the perceptual performance of both strategies, for static rendering in terms of timbre and spatial mapping, and for dynamic rendering concerning the resulting temporal continuity, overall. We found that the 5 th-order Ambisonics-based rendering strategy (ASDM) outperformed the dummy-head-based rendering for resolutions coarser than 30\({}^{\circ}\). By this and by its clear separation of room-related from head-related aspects, we consider ASDM binaural rendering as the versatile high-quality option for dynamic binaural rendering based on measured room responses. We published audio examples, an example implementation, and all experimental response data for reproducible research.  
Concerning the dummy-head-based strategy with MOBRIRs, we summarized the analysis and made available all experimental response data from previous experiments [20]. The results indicate that linear interpolation between the different dummy-head orientations is always outperformed by the linear interpolation and switched high-frequency phase method (LISHPh). This processing strategy achieved a convincing rendering quality with an orientation resolution of 15\({}^{\circ}\) and 30\({}^{\circ}\), when compared to a 1\({}^{\circ}\) linearly interpolated reference.  
The underlying RIR measurements were taken from the IEM production studio with a reverberation time of T\({}_{60}\approx 0.4\) s. This specific choice of room was found suitable to study the MOBRIR interpolation and ASDM binaural rendering as its pronounced direct and early parts are expected to be critical considering specific timbral or spatial mapping deficiencies, and its reverberation is suitable to evoke externalized impressions in typical office environments. Note that neither of the investigated rendering strategies was specifically optimized for the specific room and signals. Although not formally tested, we assume the results to hold for a variety of other acoustic environments. An example patch and a set of more reverberant BRIRs (RT = 2.8 s) are provided online ([[https://phaidra.kug.ac.at/o:100863](https://phaidra.kug.ac.at/o:100863)]([https://phaidra.kug.ac.at/o:100863](https://phaidra.kug.ac.at/o:100863))).  
Conceptualization, M.Z. and F.Z.; Writing-Original Draft Preparation M.Z. and F.Z with periodic contributions by M.F.; Writing--Review & Editing, M.Z. and F.Z.; Software, M.Z. with periodic contributions by F.Z.; Listening Experiment Implementation, F.Z. and M.Z. with periodic contributions by M.F.; Listening Experiment Design, M.Z., M.F., and F.Z.; Data Analysis, M.F. and M.Z.; Measurements, M.Z. and F.Z. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors thank all listeners for their participation in the listening experiment.  
The authors declare no conflict of interest.