# Binaural Rendering with Measured Room Responses: First-Order Ambisonic Microphone vs. Dummy Head
## 1 Introduction
Some correspondence is expected, as both the binaural Ambisonic rendering of ARIRs using MagLS [22; 23] and the interference-avoiding high-frequency strategy of MOBRIR-based rendering [20] rely on spectral phase simplification at high frequencies, and both relate to an angular resolution. To make the comparison reproducible, a room impulse response data set (dummy head and Ambisonic microphone) is measured in a studio environment and made accessible in this contribution. As the main part of the paper, Section 3 is dedicated to our comparative listening experiment on variable-orientation rendering from MOBRIRs resolved in {30\({}^{\circ}\), 45\({}^{\circ}\), 60\({}^{\circ}\)} steps and corresponding ASDM-based Ambisonic orders {5, 3, 1} rendered using the same dummy head HRIRs [21]. As the Ambisonic renderer is already available ([[https://plugins.iem.at/](https://plugins.iem.at/)]([https://plugins.iem.at/](https://plugins.iem.at/))), we dedicate Section 2 of the paper to supporting open research into MOBRIR-based rendering by providing an implementation example (Appendix A), example renderings ([[https://phaidra.kug.ac.at/view/o:77319](https://phaidra.kug.ac.at/view/o:77319)]([https://phaidra.kug.ac.at/view/o:77319](https://phaidra.kug.ac.at/view/o:77319))), listening test response data ([[https://opendata.iem.at/projects/listening_experiment_data/](https://opendata.iem.at/projects/listening_experiment_data/)]([https://opendata.iem.at/projects/listening_experiment_data/](https://opendata.iem.at/projects/listening_experiment_data/))), and a summarized statistical analysis of research presented at AES IIA [20]. In both listening experiments, participants are asked to rate for static rendering the perceptual attributes (i) timbre, (ii) spatial mapping, and for dynamic rendering (iii) its continuity. Both experiments compare the renderers to coarse linear MOBRIR interpolation (anchor) and to linear interpolation from 1\({}^{\circ}\) MOBRIRs (reference). _Measurements:_ The RIR measurements used here are available online ([[https://opendata.iem.at/projects/binauralroomresponses/](https://opendata.iem.at/projects/binauralroomresponses/)]([https://opendata.iem.at/projects/binauralroomresponses/](https://opendata.iem.at/projects/binauralroomresponses/))) and were taken from the IEM production studio (volume 127 m\({}^{3}\), base area 42 m\({}^{2}\), T\({}_{60}\approx\) 0.4 s) in which Neumann (Germany) KH310-A loudspeakers are mounted in various directions. MOBRIRs were measured with a Neumann KU100 dummy head in rotations of 1\({}^{\circ}\) steps (turntable) using the exponentially swept sine technique. Available loudspeaker directions that are depicted in Figure 1a, Figure 1b show the dummy head in the center listening position, facing the center loudspeaker (channel 3). The B-format ARIRs were measured after replacing turntable and dummy head with the Soundfield ST450 array. The room was selected for studying MOBRIRinterpolation and binaural Ambisonic rendering as the presence of its short reverberation already supports externalization in typical listening environments and its pronounced direct and early parts are expected to be critical considering both timbral artifacts and spatial mapping deficiencies [15; 24].