Gavin Kearney

• University of York

At the 2023 AES International Conference on Spatial and Immersive Audio, a networked immersive audio concert was performed. A vocal octet connected over the Internet between York and Huddersfield and provided a performance that was auralized in the acoustics of BBC Maida Vale Studio 2. A live audience in Huddersfield experienced the concert with lo...

A well-known issue in clinical audiology and hearing research is the level of abstraction of traditional experimental assessments and methods, which lack ecological validity and differ significantly from real-life experiences, often resulting in unreliable outcomes. Attempts to deal with this matter by, for example, performing experiments in real-l...

Traditional head-related transfer function acoustic measurement methods can be timeconsuming, repetitive, and require complex equipment. Although numerical simulation such as the boundary element method offers an alternative approach, creating the required accurate 3D mesh of a subject can also be time-consuming and complex, typically involving sca...

Previous studies have shown that autistic people often display atypical responses when processing sensory information, with particular prevalence within the auditory domain. Often provoked by common everyday sounds, auditory hypersensitivity can result in self-regulatory fear responses. This can be potentially harmful to autistic individuals and th...

This paper presents a study evaluating the perceptual similarity between artificial reverberation algorithms and acoustic measurements. An online headphone-based listening test was conducted and data were collected from 20 expert assessors. Seven reverberation algorithms were tested in the listening test, including the Dattorro, Directional Feedbac...

Individuals diagnosed with autism spectrum disorder (ASD) are characterised as experiencing impairments in social-emotional interaction and communication, alongside frequently displaying repetitive behaviours and interests. Further to this, they are often described as experiencing difficulties in processing sensory information, with particular prev...

In this paper we present a complete acoustic survey of the British Broadcasting Corporation Maida Vale recording studios. The paper outlines a fast room acoustic measurement framework for capture of spatial impulse response measurements for use in three or six degrees of freedom Virtual Reality rendering. Binaural recordings from a KEMAR dummy head...

This paper presents a study on the perceived importance of different acoustic parameters of Binaural Room Impulse Response (BRIR) rendering. A headphone-based listening test was conducted with twenty expert participants. Three BRIRs generated from simulations of three different rooms were convolved with a dry speech signal and used as reference aud...

Although the difference between the fast Fourier transforms of two audio signals is often used as a basic measure of predicting perceived colouration, these signal measures do not provide information on how relevant the results are from a perceptual point of view. This paper presents a perceptually motivated loudness calculation for predicting the...

This paper explores the creation of an alternative to traditional Audio Description for visually impaired film and television audiences. The Enhanced Audio Description (EAD) methods utilise sound design as the main vehicle for accessibility and advocate for the integration of accessibility practices to filmmaking workflows. Moreover, this integrate...

The Enhancing Audio Description project explored the design of an alternative to traditional Audio Description for film and television for visually impaired audiences, by maximising the potential of sound design strategies for storytelling. The project’s methodology sits within the field of accessible filmmaking, advocating for the integration of a...

Spherical harmonic (SH) interpolation is a commonly used method to spatially up-sample sparse head related transfer function (HRTF) datasets to denser HRTF datasets. However, depending on the number of sparse HRTF measurements and SH order, this process can introduce distortions into high frequency representations of the HRTFs. This paper investiga...

Spherical harmonic (SH) interpolation is a commonly used method to spatially up-sample sparse Head Related Transfer Function (HRTF) datasets to denser HRTF datasets. However, depending on the number of sparse HRTF measurements and SH order, this process can introduce distortions in high frequency representation of the HRTFs. This paper investigates...

Enhancing Audio Description is a research project that explores how sound design, first-person narration and binaural audio could be utilised to provide accessible versions of films for visually impaired audiences, presenting an alternative to current Audio Description practices. The present article explores such techniques in the context of the re...

Individuals with autism spectrum disorder (ASD) are characterised as having impairments in social-emotional interaction and communication, alongside displaying repetitive behaviours and interests. Additionally, they can frequently experience difficulties in processing sensory information with particular prevalence in the auditory domain. Often trig...

Binaural Ambisonic rendering can be achieved using virtual loudspeakers through head-related impulse response (HRIR) convolution of the Ambisonic loudspeaker feeds. It is widely used in immersive applications such as virtual reality due to its sound field rotation capabilities and low channel count. Binaural Ambisonic reproduction is inaccurate at...

In virtual reality applications, where Ambisonic audio is presented to the user binaurally (over headphones) in conjunction with a head-mounted display, retained immersion relies on congruence between the auditory and visual experiences. Therefore frontal accuracy of binaural Ambisonic audio is an area of interest. A previously introduced method fo...

Virtual Reality (VR) has been an active area of research in the development of interactive interventions for individuals with autism spectrum disorder (ASD) for over two decades. These immersive environments create a safe platform in which therapy can address the core symptoms associated with this condition. Recent advancements in spatial audio ren...

The increasing popularity of Ambisonics as a spatial audio format for streaming services poses new challenges to existing audio coding techniques. Immersive audio delivered to mobile devices requires an efficient bitrate compression that does not affect the spatial quality of the content. Good localizability of virtual sound sources is one of the k...

The increasing popularity of Ambisonics as a spatial audio format for streaming services poses new challenges to existing audio coding techniques. This paper seeks to evaluate timbral distortion and localization accuracy of Ambisonic audio encoded using Opus low-bitrate compression. The study was conducted for 1 st , 3 rd and 5 th order Ambisonic s...

Binaural Ambisonic rendering is widely used in immersive applications such as virtual reality due to its sound field rotation capabilities. An issue of low-order Ambisonics is that interaural level differences (ILDs), a crucial cue for horizontal localisation, are often reproduced lower than they should be, which reduces lateralisation. This paper...

Featured Application The methods presented in this paper improve high-frequency reproduction of binaural Ambisonic rendering. Abstract Ambisonics is a spatial audio technique appropriate for dynamic binaural rendering due to its sound field rotation and transformation capabilities, which has made it popular for virtual reality applications. An iss...

There is a growing body of academic research aiming to quantify and understand the associated health and well being benefits of group singing. The social interaction is known to strongly contribute to perceived improvements to mental and physical health but there are also indications that singing together elicits better well being outcomes that oth...

Individuals with autism spectrum disorders (ASD), who exhibit developmental limitations in social-emotional interaction and communication, are widely reported to respond positively to music therapy interventions that incorporate active and improvisational techniques. The fundamental elements of music have been shown to bypass both cognitive and lan...

As binaural audio continues to permeate immersive technologies, it is vital to develop a detailed understanding of the perceptual relevance of HRTFs. Previous research has explored the benefit of individual HRTFs with respect to localisation. However, localisation is only one metric with which it is possible to rate spatial audio. This paper evalua...

Ambisonics has enjoyed a recent resurgence in popularity due to virtual reality applications. Low order Ambisonic reproduction is inherently inaccurate at high frequencies, which causes poor timbre and height localisation. Diffuse-Field Equalisation (DFE), the theory of removing direction-independent frequency response, is applied to binaural (over...

Binaural based machine learning applications generally require a large number of HRTF (Head-Related Transfer Function) measurements. However, building an HRTF database from measurements of a large number of participants can be a time-consuming and tedious process. An alternative method is to combine the data from different existing databases to cre...

Audio Description for film and television is a pre-recorded track that uses verbal descriptions to provide information on visual aspects of a film or TV programme. In the UK it is currently the only accessibility strategy available for visually impaired audiences and although it provides access to a large number of people, its shortcomings also fai...

The human auditory system is more accurate at localising sounds in front than at lateral, rear and elevated directions. In virtual reality applications, where Ambisonic audio is presented to the user binaurally (over headphones) in conjunction with a head-mounted display, it is imperative that audio in the frontal direction is as accurate as possib...

Binaural audio research frequently employs head-related transfer functions (HRTFs). However, acoustic measurement of large numbers of HRTFs can be impractical. An alternative is boundary element method (BEM) simulation using 3D meshes. This paper describes the acoustic validation of a 3D mesh of KEMAR, previously validated against the manufacturer’...

Natural channel separation (NCS) refers to the level of acoustic isolation which exists naturally between the ears for a single sound source. To the authors’ knowledge, no systematic study has been undertaken to identify source positions which can produce the required level of NCS for binaural reproduction to be achieved without using crosstalk can...

In audio engineering research, repeatability is paramount. Speech is a great stimulus to use when evaluating audio systems, as it is a real world sound highly familiar to the human auditory system. With a view to the comparison of real and simulated sound fields, a repeatable speech source is therefore highly beneficial. This paper presents both an...

Timbre is a crucial element of believable and natural binaural synthesis. This paper presents a method for diffuse-field equalisation of first-order Ambisonic binaural rendering, aiming to address the timbral disparity that exists between Ambisonic rendering and head related transfer function (HRTF) convolution, as well as between different Ambison...

Poster derived from work on acoustic validation of BEM mesh of KEMAR

Poster derived from work to create and numerically validate a mesh model of KEMAR suitable for use within boundary element method simulation.

It has been shown that echolocation in humans, while not as advanced as other species, is a viable method of navigation. Where guide dogs and canes are vital tools for many visually impaired individuals, as of yet there are very few tools developed to aid them navigate a space using auditory cues alone. Although possible, the learning process for e...

Head and torso simulators are used extensively within acoustic research, often in place of human subjects in time-consuming or repetitive experiments. Particularly common is the Knowles Electronics Manikin for Acoustic Research (KEMAR), which has the acoustic auditory properties of an average human head. As an alternative to physical acoustic meas...

In this paper, we investigate the perception of height cues in motion-tracked transaural reproduction. 10 subjects were asked to localise sounding objects with height in a two-loudspeaker head-tracked transaural reproduction setup. Features of the head related transfer function (HRTF) for height perception were tested with generic HRTFs from a KEMA...

In this paper we investigate the perception of sound source distance in relation to static and dynamic binaural systems. Reference data for distance perception in the median plane is first presented, which shows through subjective evaluation that under the test conditions there is no perceived difference in distance perception with sound sources pr...

In this paper we investigate possibilities and limitations in terms of elevated sound source reproduction using higher order Ambisonics and practical loudspeaker configurations. Reconstructed sound fields are analysed from the point of view of reproduced energy, sound field reconstruction error and distortion of high frequency spectrum which contai...

|We investigated the impact of exploratory head movements on sound localization accuracy using real and virtual 5.1 loudspeaker arrays. Head orientation data in the horizontal plane was provided either by the Microsoft Kinect face-tracking or Oculus Rift's built-in Inertial Measurement Unit (IMU) which resulted in signi�cantly di�erent precision an...

The present paper provides an insight into the acoustic characteristics of one of the spaces used for the performance of the York Mystery Plays: Stonegate, a street in central York (UK). An experiment conducted in a controlled environment with the aim of determining the optimal method for acoustic measurements on this site is first presented. The m...

In this paper, we present and describe the sound design and audio evaluation of Viking Ghost Hunt, a location-aware game based around important historical locations in Dublin, Ireland. We describe the novel approach taken in developing an engaging soundscape for location-aware games in mobile multimedia devices that highlight the importance of spat...

In this paper, an investigation into the localisation accuracy of Higher Order Ambisonic sound elds with reference to Vector Based Amplitude Panning (VBAP) is presented. The analysis is considered in relation to listeners who are not located in the acoustic sweet spot. The performance of velocity, energy, in-phase and psychoacoustically optimized A...

A factorization technique is proposed which allows for a direction independent component to be extracted from a set of head related impulse responses (HRIRs). Each individual HRIR is split into a pair of filters, a direction independent component which is common to all HRIRs in the dataset and a direction dependent component which is particular to...

Spatial localisation of sounding objects is affected not only by auditory cues but also by other modalities such as vision. This is true particularly in the context of distance perception where the number of auditory cues is limited in comparison to e.g. localisation in horizontal and vertical planes. In this study we investigate the influence of v...

The use of multiple audio streams from digital mixing consoles is presented for application to real-time enhancement of synchronised visual effects in live music performances. The audio streams are processed simultaneously and their temporal and spectral characteristics can be used to control the intensity, duration and colour of the lights. The ef...

We present an integrated set of audio-visual tracking and synthesis tools to aid matching of the audio to the video position in both horizontal and periphonic sound reinforcement systems. Compensation for screen size and loudspeaker layout for high definition formats is incorporated and the spatial localisation of the source is rendered using advan...

In this paper, we present an investigation into the perception of source distance in interactive virtual auditory environments in the context of First (FOA) and Higher Order Ambisonic (HOA) reproduction. In particular, we investigate the accuracy of sound field reproduction over virtual loudspeakers (headphone reproduction) with increasing Ambisoni...

Ambisonics is a surround sound technique developed in the 1970s by Michael Gerzon and colleagues at theMathematical Institute of Oxford. Ambisonics is often criticized for its small sweet spot area. This can be improved byincreasing the order of the Ambisonic microphone through the use of higher-order spherical harmonics.This project consists of th...

Although both auditory and visual information can influence the perceived emotion of an individual, how these modalities contribute to the perceived emotion of a crowd of characters was hitherto unknown. Here, we manipulated the ambiguity of the emotion of either a visual or auditory crowd of characters by varying the proportions of characters expr...

In this paper, we present an improved model for Interaural Time Difference (ITD) estimation in reverberant environments. The Phase Transform (PHAT) weighting function, used in generalized cross correlation is investigated here for application to Interaural Cross Correlation (IACC) measurements from binaural microphones. A binaural model is develope...

This paper introduces a new database of freely available stereo-3D content designed to facilitate research in stereo post-production. It describes the structure and content of the database and provides some details about how the material was gathered. The database includes examples of many of the scenarios characteristic to broadcast footage. Mater...

In this paper we present a method for spatial audio reproduction over headphones using Head-Related Impulse Response (HRIR) simplification and Ambisonic decoding. The method is shown to significantly reduce computational complexity for real-time audio based rendering by decomposing the directional component of HRIRs into spherical harmonic basis fu...

HRIR factorisation allows the extraction of a common direction independent component from a set of HRIRs leaving a set of relatively short direction dependent filters and provides both memory and computational savings in real time spatial audio applications. In this paper this technique is improved by introducing weighted regularisation to the iter...

An approach to approximation of Binaural Room Impulse Responses (BRIRs) is presented. Here, a BRIR is considered to have two constituent parts: the anechoic Head Related Impulse Response (HRIR), convolved with the Room Impulse Response (RIR). Each part is approximated individually. The HRIR is partitioned as the convolution of a directional indepen...

In this paper we explore the source localisation accuracy and perceived spatial distortion of a source separation based upmix algorithm for 2 to 5 channel conversion. Unlike traditional upmixing techniques, source separation based techniques allow individual sources to be separated from the mixture and repositioned independently within the surround...

We present a method to extract a common subsystem from a HRIR dataset to allow for easier real-time convolution in interactive audio environments and more efficient HRIR in-terpolation. An iterative least squares method is described for this deconvolution operation, and the relation of this method to that of finding the approximate greatest common...

The performance of various spatialization techniques is evaluated for a distributed audience using the non-ideal speaker arrangements found in small concert halls. The methods under evaluation are Second Order Ambisonics, Vector Base Amplitude Panning, Delta Stereophony and Spat with B-format Ambisonics encod-ing. Each method is assessed in terms o...

A comparison of several spatialization systems is presented in terms of their localization accuracy under the nonideal listening conditions found in typical small concert halls. Of interest is the effect of real reverberant conditions, noncentral listening positions, and nonsymmetrical speaker arrays on source localization. The data are presented b...

E-Learning environments which merge traditional classroom instruction with teleconference capabilities are found to overlook the importance of correct localization of both stationary and mobile sound sources for all audience members with the video data on a teleconference screen. Research into conventional sound reinforcement solutions shows how sy...

In this paper, we present an investigation into the perception of source depth in interactive virtual auditory environments in the context of Higher Order Ambisonic (HOA) reproduction. In particular, we investigate the accuracy of soundfield reproduc-tion over virtual loudspeakers (headphone reproduction) with in-creasing Ambisonic order. Performan...

The transfer of multichannel spatialization schemes from the stu-dio to the concert hall presents numerous challenges to the con-temporary spatial music composer or engineer. The presence of a reverberant listening environment coupled with a distributed audi-ence are significant factors in the presentation of multichannel spa-tial music. This paper...

In this paper, we present a framework for recording real musical auditory scenes for interactive virtual acoustic reproduction over headphones. The framework considers the parameterization of real-world soundfields and subsequent real-time auralization us-ing a hybrid image source method/measurement-based auraliza-tion approach. First Order (FOA) a...