Analyses on limitations of binaural sound based on the first order Ambisonics for virtual reality audio (original) (raw)

3D binaural sound reproduction using a virtual ambisonic approach

IEEE International Symposium on Virtual Environments, Human-Computer Interfaces and Measurement Systems, 2003. VECIMS '03. 2003, 2003

A --Convincing binaural sound reprodudion via headphones requires fofllfer the virfual sound source signals wifh head relafed transfer funcfions (HRTFs). Furfhermore, humnns are able lo improve fheir locdimfion capabilifies by smoll unconscious head movemenfs. Therefore it is imporfant fa incorporate head-tracking. This yields fheproblem of high-quality, rime-varying interpolation between dvferent HRTFs A funher improvemenf of humnns Iocalizafion accuracy can be done by considering room simulafion yielding a huge nmounf of virtual sound sources. To increase the computafional eflciency offhe proposed sysfem a virfual Ambisonic approach is used, fhaf resulfs in a bank offimeinvarinnf HRTFJXfer independenf of fhe number of sources Io encode

Perceptual assessment of binaural decoding of first-order ambisonics

The first-order Ambisonics microphone (e.g. Soundfield®) is a both compact and efficient setup for spatial audio recording with the benefit of a full 3D spatialization. Another advantage is that the signals delivered by this microphone (i.e. B-Format) can be rendered over headphones by applying appropriate processing, while ensuring that the 3D spatial information is preserved. With the growing use of personal devices, it should be considered that most audio content is listened to over headphones. Thus first order Ambisonics recording provides an attractive solution to pickup 3D audio content compatible with headphone reproduction. "Binaural decoding" refers to the processing to adapt B-Format for headphone rendering (i.e. "binaural format"). One solution is based on binaural synthesis of virtual loudspeakers. One promising way to improve the decoding is active processing which takes information from a pre-analysis of the sound scene, particularly in terms of spatial information. This paper will compare various binaural decoders. Starting from a listening test which assesses existing solutions and which shows that the perceived quality may strongly vary from one decoder to another, the processing is analyzed step by step. The performances are measured by a set of objective criteria derived from localization cues.

Ambisonic Based Binaural Sound Reproduction System

2005

A computationally efficient 3D real time rendering engine for binaural sound reproduction via headphones is presented. Binaural sound reproduction requires to filter the virtual sound source signals with head related transfer functions (HRTFs). To improve humans localization capabilities head tracking as well as room simulation have to be incorporated. This yields the problem of high-quality, time-varying interpolation between different HRTFs. To overcome this problem a virtual ambisonic approach is used that results in a bank of time-invariant HRTF filter.

A 3D Ambisonic Based Binaural Sound Reproduction System

2003

Analysis of Binaural Technology and Surround Rendering for Headphones Reproduction

This research is based on the Binaural rendering from Surround sound. As Binaural and Surround systems are becoming more accurate and able to give a fully-immersive perception of sound through headphones, the importance of understanding how these systems work is necessary to better use, develop, and implement Binaural in the everyday routine. Binaural, its history, features and limitations has been analysed. Surround systems, such as 5.1 and Ambisonics, have been analysed and compared for Binaural Rendering purposes. Ambisonics has shown that its versatility and 360 degrees spatial audio characteristics can be used to accurately render Binaural signals.

Analysis of binaural cue matching using ambisonics to binaural decoding techniques

2017

Last year Google enabled spatial audio in head-tracked 360 videos using Ambisonics to binaural decoding on Android mobile devices. There was some early criticism of the 1st order to binaural conversion employed by Google, in terms of the quality of localisation and noticeable frequency response colouration. In this paper, the algorithm used by Google is discussed and the Ambisonics to Binaural conversion using virtual speakers analysed with respect to the resulting inter-aural time, level, and spectrum differences compared to an example HRTF data set. 1st to 35th order Ambisonics using multiple virtual speaker arrays are implemented and analysed with inverse filtering techniques for smoothing the frequency spectrum also discussed demonstrating 8th order decoding correctly reproducing binaural cues up to 4 kHz.

Ambisonic sound in virtual environments and applications for blind people

1998

To date there has been much more effort directed to generating credible presentations of virtual worlds in a visual medium than in reproducing corresponding or even self contained worlds with synthesised or recorded sound. There is thus today a disparity in the relative fidelity of these 2 modes in most VR systems. While much work has been done in hi-fidelity and dimensional sound reproduction in psycho-acoustic research and applications for audiophiles this has rarely been taken onboard by the VR community. This paper describes work ongoing to apply Ambisonic techniques to the generation of audio virtual worlds and environments. Firstly Ambisonics is briefly outlined then principles behind its implementation in this context described. The design of the implementations to date is described and the results of trials discussed. The strengths and limitations of the approach are discussed in the light of this practical experience. There is a range of applications envisaged for this tech...

Binaural technology for e.g. rendering auditory virtual environments

The Journal of the Acoustical Society of America, 2008

Jens Blauert's research up through the late 60ties and later, pioneered the field of binaural technology and auditory virtual environments. He mastered the measurement of head-related transfer functions (HRTFs) before the term was introduced, and his methods were standard for decades. While most acknowledge his efforts in understanding the binaural hearing and the significance of inter-aural differences, appreciation is also in place for his evaluation of localization with identical ear input signals. The relations between the hearing's "directional" bands and the transfer functions' "boosted" bands, helped mediate the understanding that if the transfer functions could be mastered, then important dimensions of the auditory percept could also be controlled. He early understood the potential of using the HRTFs and numerical sound transmission analysis programs for rendering auditory virtual environments. Jens Blauert participated in many European cooperation projects exploring this field (and others), among other the SCATIS project addressing the auditory-tactile dimensions in the absence of visual information.

Analyses on limitations of binaural sound based on the first order Ambisonics for virtual reality audio (original) (raw)

Related papers