On the authenticity of individual dynamic binaural synthesis

Abstract

A simulation that is perceptually indistinguishable from the corresponding real sound field could be termed authentic. Using binaural technology, such a simulation would theoretically be achieved by reconstructing the sound pressure at a listener's ears. However, inevitable errors in the measurement, rendering, and reproduction introduce audible degradations, as it has been demonstrated in previous studies for anechoic environments and static binaural simulations (fixed head orientation). The current study investigated the authenticity of individual dynamic binaural simulations for three different acoustic environments (anechoic, dry, wet) using a highly sensitive listening test design. The results show that about half of the participants failed to reliably detect any differences for a speech stimulus, whereas all participants were able to do so for pulsed pink noise. Higher detection rates were observed in the anechoic condition, compared to the reverberant spaces, while the source position had no significant effect. It is concluded that the authenticity mainly depends on how comprehensive the spectral cues are provided by the audio content, and the amount of reverberation, whereas the source position plays a minor role. This is confirmed by a broad qualitative evaluation, suggesting that remaining differences mainly affect the tone color rather than the spatial, temporal or dynamical qualities.

The “Missing 6 dB” Revisited: Influence of Room Acoustics and Binaural Parameters on the Loudness Mismatch Between Headphones and Loudspeakers

“…However, there is considerable evidence in the literature (see below) about a mismatch between headphone and loudspeaker presentation violating the "matching assumption" for yet unclear reasons. This contrasts with findings from more recent research Brinkmann et al, 2017) indicating that virtually no mismatch occurs if the individual sound filtering properties are adequately taken into account (i.e., using individual head related transfer functions, HRTFs, and headphone related transfer functions, HpTFs), thus ensuring that the same waveforms are created at the eardrums in both presentation modes. However, the reason why these studies provide contradicting findings and how the mismatch between headphone and loudspeaker listening might depend on the different experimental parameters employed in the various studies in the literature is yet unclear.…”

Auralization of acoustic spaces based on spherical microphone array recordings

“…One then speaks of dynamic or head-tracked binaural reproduction. The result is a tremendous improvement in terms of spatial fidelity 9,10 as far as the binaural playback being almost or fully indistinguishable from a real sound source 11 .…”

Interaural Level Difference Optimization of Binaural Ambisonic Rendering

“…where σ = ±1, P mn (sin φ) are the associated Legendre functions [32] of order m and degree n and m = 2 − δ n,0 where δ n,0 = 1 when n = 0 and δ n,0 = 0 otherwise. To accurately decode three-dimensional Ambisonic signals, a spherical array of loudspeakers distributed with at least semi-regularity is necessary with a number of loudspeakers L ≥ K. A re-encoding matrix C with K rows and L columns is calculated by encoding the position of each loudspeaker into SH coefficients using (3). A mode matching decoding matrix D is then calculated from the pseudo-inverse of C [14] such that…”

“…When rendering binaural audio, recreating the spatial cues as realistically as possible will improve the plausibility and authenticity of the auditory experience [2,3]. Individualized HRIR measurements therefore produce more accurate localization cues and timbre than non-individualized HRIRs [4,5], such as those acquired from a dummy head.…”