Joint sampling theory and subjective investigation of plane-wave and spherical harmonics formulations for binaural reproduction

Ben-Hur, Zamir; Sheaffer, Jonathan; Rafaely, Boaz

doi:10.1016/j.apacoust.2018.01.016

Cited by 13 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…with N ¼ min N a , N h ðÞ [44], where N a and N h are the maximum available order of the Ambisonics signals and the HRTF, respectively. For example, when the Ambisonics signal is derived from spherical microphone array recordings, such as the Eigenmike [45], its order will be limited by the number of microphones; for the Eigenmike case with 32 microphones its order is around N a ¼ 4 [46].…”

Section: Basic Ambisonics Reproductionmentioning

confidence: 99%

Binaural Reproduction Based on Bilateral Ambisonics

Ben-Hur¹,

Alon²,

Berebi³

et al. 2022

Advances in Fundamental and Applied Research on Spatial Audio

Self Cite

View full text Add to dashboard Cite

Binaural reproduction of high-quality spatial sound has gained considerable interest with the recent technology developments in virtual and augmented reality. The reproduction of binaural signals in the Spherical-Harmonics (SH) domain using Ambisonics is now a well-established methodology, with flexible binaural processing realized using SH representations of the sound-field and the Head-Related Transfer Function (HRTF). However, in most practical cases, the binaural reproduction is order-limited, which introduces truncation errors that have a detrimental effect on the perception of the reproduced signals, mainly due to the truncation of the HRTF. Recently, it has been shown that manipulating the HRTF phase component, by ear-alignment, significantly reduces its effective SH order while preserving its phase information, which may be beneficial for alleviating the above detrimental effect. Incorporating the ear-aligned HRTF into the binaural reproduction process has been suggested by using Bilateral Ambisonics, which is an Ambisonics representation of the sound-field formulated at the two ears. While this method imposes challenges on acquiring the sound-field, and specifically, on applying head-rotations, it leads to a significant reduction in errors caused by the limited-order reproduction, which yields a substantial improvement in the perceived binaural reproduction quality even with first order SH.

show abstract

Section: Basic Ambisonics Reproductionmentioning

confidence: 99%

Binaural Reproduction Based on Bilateral Ambisonics

Ben-Hur¹,

Alon²,

Berebi³

et al. 2022

Advances in Fundamental and Applied Research on Spatial Audio

Self Cite

View full text Add to dashboard Cite

show abstract

“…Examples of aliasing patterns for different sampling schemes and detailed discussion about the aliasing matrix can be found in Refs. [19,21,40]. Note, further, that is frequency independent; therefore, the aliasing error is expected to increase when the magnitude of high-order coefficients of the HRTF increases, which happens at high frequencies.…”

Section: Spatial Aliasing In Hrtf Measurementmentioning

confidence: 99%

Loudness stability of binaural sound with spherical harmonic representation of sparse head-related transfer functions

Ben-Hur

Alon

Rafaely

et al. 2019

J AUDIO SPEECH MUSIC PROC.

Self Cite

View full text Add to dashboard Cite

In response to renewed interest in virtual and augmented reality, the need for high-quality spatial audio systems has emerged. The reproduction of immersive and realistic virtual sound requires high resolution individualized head-related transfer function (HRTF) sets. In order to acquire an individualized HRTF, a large number of spatial measurements are needed. However, such a measurement process requires expensive and specialized equipment, which motivates the use of sparsely measured HRTFs. Previous studies have demonstrated that spherical harmonics (SH) can be used to reconstruct the HRTFs from a relatively small number of spatial samples, but reducing the number of samples may produce spatial aliasing error. Furthermore, by measuring the HRTF on a sparse grid the SH representation will be order-limited, leading to constrained spatial resolution. In this paper, the effect of sparse measurement grids on the reproduced binaural signal is studied by analyzing both aliasing and truncation errors. The expected effect of these errors on the perceived loudness stability of the virtual sound source is studied theoretically, as well as perceptually by an experimental investigation. Results indicate a substantial effect of truncation error on the loudness stability, while the added aliasing seems to significantly reduce this effect.

show abstract

“…see the "magnitude least squares" method, or MagLS [11]). Additionally, Ben-Hur et al [12] have shown that the virtual loudspeaker method can be derived with the SH-based formulation (this is further discussed in Section 2), meaning that the latter provides a more general solution to the binaural decoding problem. For this reason, the SH-based formulation is employed in the present study.…”

Section: Introduction 1binaural Rendering and Ambisonicsmentioning

confidence: 99%

Assessing HRTF preprocessing methods for Ambisonics rendering through perceptual models

2022

View full text Add to dashboard Cite

Binaural rendering of Ambisonics signals is a common way to reproduce spatial audio content. Processing Ambisonics signals at low spatial orders is desirable in order to reduce complexity, although it may degrade the perceived quality, in part due to the mismatch that occurs when a low-order Ambisonics signal is paired with a spatially dense head-related transfer function (HRTF). In order to alleviate this issue, the HRTF may be preprocessed so its spatial order is reduced. Several preprocessing methods have been proposed, but they have not been thoroughly compared yet. In this study, nine HRTF preprocessing methods were used to render anechoic binaural signals from Ambisonics representations of orders 1 to 44, and these were compared through perceptual hearing models in terms of localisation performance, externalisation and speech reception. This assessment was supported by numerical analyses of HRTF interpolation errors, interaural differences, perceptually-relevant spectral differences, and loudness stability. Models predicted that the binaural renderings’ accuracy increased with spatial order, as expected. A notable effect of the preprocessing method was observed: whereas all methods performed similarly at the highest spatial orders, some were considerably better at lower orders. A newly proposed method, BiMagLS, displayed the best performance overall and is recommended for the rendering of bilateral Ambisonics signals. The results, which were in line with previous literature, indirectly validate the perceptual models’ ability to predict listeners’ responses in a consistent and explicable manner.

show abstract

Joint sampling theory and subjective investigation of plane-wave and spherical harmonics formulations for binaural reproduction

Cited by 13 publications

References 20 publications

Binaural Reproduction Based on Bilateral Ambisonics

Binaural Reproduction Based on Bilateral Ambisonics

Loudness stability of binaural sound with spherical harmonic representation of sparse head-related transfer functions

Assessing HRTF preprocessing methods for Ambisonics rendering through perceptual models

Contact Info

Product

Resources

About