Perceived Quality of Binaural Rendering from Baffled Microphone Arrays Evaluated Without an Explicit Reference

The authors present a perceptual evaluation of the binaural rendering quality of signals from several types of baffled microphone arrays. They employ the multi-stimulus category rating (MuSCR) paradigm that does not require a reference stimulus. The tested conditions also comprise a very high numerical accuracy stimulus, given the highest quality rating in approximately half of the multi-stimulus trials. A comparison with the literature on spherical microphone arrays (SMAs) shows that MuSCR allows for drawing representative conclusions regarding the dependency of the perceived quality on the array and rendering parameters as in previous experiments with an explicit high-fidelity reference. The authors applied the MuSCR paradigm to evaluate the perceived reproduction quality of equatorial microphone arrays (EMAs) with microphones only along the equator of the spherical baffle and of equatorial arrays with a nonspherical baffle (XMAs). The results endorse the observations from SMAs that an increasing spherical harmonic order leads to improved perceived quality. The authors also confirm that EMAs lead to the same perceived quality as SMAs despite the substantial difference in the number of microphones. Magnitude equalization of artifacts from spatial undersampling can be very effective for XMAs the raw solution deviates significantly from the other array types at high frequencies.