The OperaRIR dataset contains acoustical measurements conducted in the main auditorium of the Finnish National Opera and Ballet (FNOB), a modern-shaped horseshoe opera hall located in Helsinki, Finland. This type of hall contains multi-slopes and direction- and frequency-dependent decay characteristics. As such, this dataset is suitable for research in the field of directional and multi-slope decay analysis as well as 6DoF auralization. Dataset In this measurement campaign, 210 spatial room impulse responses (SRIR) were measured. More specifically, 97 individual seats on the parterre were measured sequentially using two different sound sources located on the stage for a total of 194 SRIRS. Four were selected as validation points among these measurement positions, and two extra measurement sets were performed using the same two sound sources, thus adding 16 SRIRs to the dataset. These validation points are intended for use in assessing the stability of the measurements and the background noise. The measurements were captured using a spherical microphone array (SMA), the Eigenmike (https://mhacoustics.com/), to obtain microphone signals that can be encoded as fourth-order ambisonic SRIRs. Two Genelec 8331A loudspeakers were used as sound sources and both were positioned at a depth of one meter, from the edge of the stage, on a 1.6m stand. The first source was located 5.53m from the lateral center, on the left side of the stage when looking from the parterre, and the second loudspeaker was situated in the center. Other than the loudspeakers, the stage was left empty, the curtain was fully raised, and no audience was present. For each measurement position, the microphone was aligned to face directly toward the sound source in the center of the stage (source 2) as a common reference point. The microphone signals are made available as measured, and the layout data file contains the rotation angles necessary to correctly align each measured position to a common plane, in the back of the stage. The files encoded in Ambisonics have been rotated to compensate for this initial alignment, and are all pointing towards the main stage. The location of each microphone position was obtained using a top-view architectural plan of the hall (OperaRIR_measurement_layout.pdf). The coordinate system used here is in meters and the axis origin is located in the top left corner of the architectural plan, the two loudspeakers are positioned at y=0. As such, the coordinates of the first source are (7.30, 0.0), and the second source is located at (12.83, 0.0). Each SRIR file is named according to the following convention : ____.wav refers to either em32 microphone signals (mic), or Ambisonics format (hoa). For example Row4_Seat124_Source2_mic_48k The dataset contains: • An architectural overview of the hall and the measured seats (OperaRIR_measurement_layout.pdf) • A file containing the XY coordinate of each measurement point and the rotation (OperaRIR_layout.mat) • Measured SRIR from the control positions (OperaRIR_control_points_rir.zip) • Measured DRIR from the em32 SMA as raw microphone signals (OperaRIR_em32_microphones_48k.zip) • Measured SRIR rotated and encoded in 4th order Ambisonics (OperaRIR_hoa4_sn3d_48k.zip) For more information on the measurement procedure, please refer to the published article. Reference: B. Alary and A. Politis, "A Dataset for Location- and Direction-Dependent Reverberation Analysis," in Proc. 10th Convention of the European Acoustics Association, (Turin, Italy), Sep. 2023 Please use the above citation to refer to the dataset in a publication.

2023