scholarly journals Binaural Reproduction Based on Bilateral Ambisonics

2021 ◽  
Author(s):  
Zamir Ben-Hur ◽  
David Alon ◽  
Or Berebi ◽  
Ravish Mehra ◽  
Boaz Rafaely
Keyword(s):  
Detrimental Effect ◽  
Sound Field ◽  
Substantial Improvement ◽  
Binaural Processing ◽  
Truncation Errors ◽  
Spatial Sound ◽  
Reproduction Process ◽  
Virtual And Augmented Reality ◽  
Head Related Transfer Function ◽  
Head Rotations

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.

Spatial Sound for Computer Games and Virtual Reality

2010 ◽  
pp. 287-312 ◽  
Author(s):  
David Murphy ◽  
Flaithrí Neff
Keyword(s):  
Virtual Reality ◽  
Transfer Function ◽  
Mobile Devices ◽  
Computer Games ◽  
Future Trends ◽  
Hardware System ◽  
Spatial Sound ◽  
Head Related Transfer Function ◽  
Review Current ◽  
Audio Technologies

In this chapter, we discuss spatial sound within the context of Virtual Reality and other synthetic environments such as computer games. We review current audio technologies, sound constraints within immersive multi-modal spaces, and future trends. The review process takes into consideration the wide-varying levels of audio sophistication in the gaming and VR industries, ranging from standard stereo output to Head Related Transfer Function implementation. The level of sophistication is determined mostly by hardware/system constraints (such as mobile devices or network limitations), however audio practitioners are developing novel and diverse methods to overcome many of these challenges. No matter what approach is employed, the primary objectives are very similar—the enhancement of the virtual scene and the enrichment of the user experience. We discuss how successful various audio technologies are in achieving these objectives, how they fall short, and how they are aligned to overcome these shortfalls in future implementations.

A spatial sound delivery system for virtual and augmented reality

2020 ◽  
Vol 148 (4) ◽  
pp. 2539-2539
Author(s):  
Chinmay Rajguru ◽  
Arash Pouryazdan ◽  
Gianluca Memoli
Keyword(s):  
Augmented Reality ◽  
Delivery System ◽  
Spatial Sound ◽  
Virtual And Augmented Reality

scholarly journals Efficient binaural rendering of spherical microphone array data by linear filtering

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Johannes M. Arend ◽  
Tim Lübeck ◽  
Christoph Pörschmann
Keyword(s):  
Real Time ◽  
Transfer Functions ◽  
Finite Impulse Response ◽  
Microphone Array ◽  
Sound Field ◽  
Limited Range ◽  
Time Signal ◽  
Head Orientation ◽  
Linear Filtering ◽  
Spatial Sound

AbstractHigh-quality rendering of spatial sound fields in real-time is becoming increasingly important with the steadily growing interest in virtual and augmented reality technologies. Typically, a spherical microphone array (SMA) is used to capture a spatial sound field. The captured sound field can be reproduced over headphones in real-time using binaural rendering, virtually placing a single listener in the sound field. Common methods for binaural rendering first spatially encode the sound field by transforming it to the spherical harmonics domain and then decode the sound field binaurally by combining it with head-related transfer functions (HRTFs). However, these rendering methods are computationally demanding, especially for high-order SMAs, and require implementing quite sophisticated real-time signal processing. This paper presents a computationally more efficient method for real-time binaural rendering of SMA signals by linear filtering. The proposed method allows representing any common rendering chain as a set of precomputed finite impulse response filters, which are then applied to the SMA signals in real-time using fast convolution to produce the binaural signals. Results of the technical evaluation show that the presented approach is equivalent to conventional rendering methods while being computationally less demanding and easier to implement using any real-time convolution system. However, the lower computational complexity goes along with lower flexibility. On the one hand, encoding and decoding are no longer decoupled, and on the other hand, sound field transformations in the SH domain can no longer be performed. Consequently, in the proposed method, a filter set must be precomputed and stored for each possible head orientation of the listener, leading to higher memory requirements than the conventional methods. As such, the approach is particularly well suited for efficient real-time binaural rendering of SMA signals in a fixed setup where usually a limited range of head orientations is sufficient, such as live concert streaming or VR teleconferencing.

Effects of variable acoustic elements on the spatial sound field in multipurpose venues

2017 ◽  
Vol 142 (4) ◽  
pp. 2688-2688
Author(s):  
Michelle C. Vigeant ◽  
Matthew T. Neal ◽  
David A. Dick
Keyword(s):  
Sound Field ◽  
Spatial Sound

scholarly journals Speech perception and hearing effort using a new active middle ear implant audio processor

2021 ◽  
Author(s):  
Torsten Rahne ◽  
Laura Fröhlich ◽  
Luise Wagner ◽  
Miriam Hannah Kropp ◽  
Alexander Müller
Keyword(s):  
Bone Conduction ◽  
Sound Field ◽  
Field Tests ◽  
Substantial Improvement ◽  
Fourth Generation ◽  
Listening Effort ◽  
Active Middle Ear Implant ◽  
Middle Ear Implant ◽  
Subjective Satisfaction ◽  
Improved Performance

Abstract Purpose The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA. Method Fifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES. Results Both audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA. Conclusion The SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.

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