• AmbiFreeVerb 2—Development of a 3D ambisonic reverb with spatial warping and variable scattering

      Dring, Mark; Wiggins, Bruce; University of Derby (Audio Engineering Society, 2016-07-14)
      In this paper the development of a three dimensional Ambisonic reverb based on the open source FreeVerb algorithm will be presented and discussed. This model is then extended to include processing in over-specified A-format, rather than B-format, variable scattering between channels along with controls for warping the distribution of the reflections to implement a reverb that is able to react to the source position in a spatially coherent way with an acoustical analysis of its performance.
    • Ambiguity, uncertainty and new realities: perspectives of creative value, utility and authenticity

      Wilson, Chris; Brown, Michael; University of Derby (KIE, Knowledge, Innovation & Enterprise, 2015)
      The concept of creativity is synonymous with the formulation of value judgements. Related primarily to the experience of new and unfamiliar ideas, creativity is a subject directly connected to conceptions of adjustment, re-calibration, measurement and evaluation. Albeit a subjective term open to considerable flexibility of interpretation, creativity has nevertheless become a capacity and commodity of notionally high social and economic value. Consequently, creativity has never been subject to greater scrutiny and judgement and understanding of creative value subject to greater discussion and evaluation. Exploring aspects of creativity associated with ambiguity and uncertainty through the discourse of authenticity and aesthetics, this chapter positions analysis in the narratives of insight and imagination, the romanticism of discovery and talent, and debates about the increasing virtualisation of creative practice and emerging prospect of artificial creativity. Investigating the potential for what might be described as authentic creativity, notions of forgery and fakery, serendipity, accidental discovery, and the dynamics of positive and negative creative conditions, provide a basis for focused consideration of the ‘how’ and ‘why’ of creative activity and the various ways these relate to the determination of value in the ‘what’ of creative outcomes. Exploring first the nature of creative value and closely related definitions of creativity, consideration is then given to the temporal and cultural dynamics of creative value judgements before focusing more specifically on contexts of creativity and areas of creative ambiguity. Introducing a series of illustrative case studies, discussion focuses on the parameters of creative value judgements to underpin a tentative definition of creative authenticity. Conclusions highlight a range of possible perspectives related to the subjective nature of creativity and definitions of creative value. Creativity and creative value can be determined simply according to the scale of impact on human well-being, progress, fulfilment, security, or other suitable value indicator, the quality of lived human experience, the intrinsic qualities of the object, artefact or activity, or combination of all three. Given the inherent diversity and instability of creation and reception contexts, the search for any form objective measure of creative value may be a fruitless one. However, it is in the very subjectivity of creative experience that creative authenticity is most visible.
    • Analysis, modeling and wide-area spatiotemporal control of low-frequency sound reproduction

      Hill, Adam J.; University of Essex (University of Essex, 2012-01)
      This research aims to develop a low-frequency response control methodology capable of delivering a consistent spectral and temporal response over a wide listening area. Low-frequency room acoustics are naturally plagued by room-modes, a result of standing waves at frequencies with wavelengths that are integer multiples of one or more room dimension. The standing wave pattern is different for each modal frequency, causing a complicated sound field exhibiting a highly position-dependent frequency response. Enhanced systems are investigated with multiple degrees of freedom (independently-controllable sound radiating sources) to provide adequate low-frequency response control. The proposed solution, termed a chameleon subwoofer array or CSA, adopts the most advantageous aspects of existing room-mode correction methodologies while emphasizing efficiency and practicality. Multiple degrees of freedom are ideally achieved by employing what is designated a hybrid subwoofer, which provides four orthogonal degrees of freedom configured within a modest-sized enclosure. The CSA software algorithm integrates both objective and subjective measures to address listener preferences including the possibility of individual real-time control. CSAs and existing techniques are evaluated within a novel acoustical modeling system (FDTD simulation toolbox) developed to meet the requirements of this research. Extensive virtual development of CSAs has led to experimentation using a prototype hybrid subwoofer. The resulting performance is in line with the simulations, whereby variance across a wide listening area is reduced by over 50% with only four degrees of freedom. A supplemental novel correction algorithm addresses correction issues at select narrow frequency bands. These frequencies are filtered from the signal and replaced using virtual bass to maintain all aural information, a psychoacoustical effect giving the impression of low-frequency. Virtual bass is synthesized using an original hybrid approach combining two mainstream synthesis procedures while suppressing each method‟s inherent weaknesses. This algorithm is demonstrated to improve CSA output efficiency while maintaining acceptable subjective performance.
    • Between possibilities and places: cognitive metaphor, creativity, art and education

      Brown, Michael; Wilson, Chris; University of Derby (KIE, 2013-09-10)
    • The business of invention: considering project management in the arts and industry

      Wilson, Chris; Brown, Michael; University of Derby (Knowledge, Innovation & Enterprise, 2013)
      Project management has well developed theoretical constructs and is becom- ing increasingly well established in core strategy beyond the industrial and corporate sec- tors from which it first emerged. With a concurrent increase in the significance of innova- tion, project managing for creativity is an area of research and enquiry of considerable sig- nificance. Notionally occupying polar opposite cultural positions in terms of perspectives and processes of creativity, project management in the arts is widely considered to vary significantly from corporate strategy and process. If business were to be more generally characterised by ‘organisation’ and discipline, the arts are more commonly celebrated for disorganisation, indiscipline, and the fundamental challenge to organisation itself. Consid- ering both the confluences and variations between established project management theory in business and practice in the arts, this text introduces theoretical constructs pertaining to creative processes and highlights areas for consideration in the understanding and further development of project management theory.
    • Chameleon subwoofer arrays in live sound

      Hill, Adam J.; Hawksford, Malcolm O. J.; University of Essex (Institute of Acoustics, 2011-06)
      Live-sound subwoofer systems should deliver low-frequency sound evenly distributed throughout the audience area while simultaneously minimizing sound pressure levels on stage. Approximate solutions generally exploit cardioid subwoofers and/or steerable subwoofer clusters, yet require venue-specific manual fine tuning limited mainly by practical positioning issues. Enhanced live-sound systems are explored using a virtual three-dimensional acoustic space to model dominant venue characteristics. Specifically the Chameleon Subwoofer Array (CSA) is incorporated, already proposed as a solution to small-room low-frequency sound reproduction by extending the available degrees of freedom to control sound distribution in the target space. The CSA is adapted and scaled to match the large-scale dimensions typical of live events with 3-D simulation used to optimize and validate performance. Adaptation of existing industry-standard equipment with only minor modification is presented as a core feature.
    • Conformity, deformity and reformity

      Brown, Michael; Wilson, Chris; University of Derby (West East Institute, 2015)
      In any given field of artistic practice, practitioners position themselves—or find themselves positioned—according to interests and allegiances with specific movements, genres, and traditions. Selecting particular frameworks through which to approach the development of new ideas, patterns and expressions, balance is invariably maintained between the desire to contribute towards and connect with a particular set of domain conventions, whilst at the same time developing distinction and recognition as a creative individual. Creativity through the constraints of artistic domain, discipline and style provides a basis for consideration of notions of originality in the context of activity primarily associated with reconfiguration, manipulation and reorganisation of existing elements and ideas. Drawing from postmodern and post-structuralist perspectives in the analysis of modern hybrid art forms and the emergence of virtual creative environments, the transition from traditional artistic practice and notions of craft and creation, to creative spaces in which elements are manipulated, mutated, combined and distorted with often frivolous or subversive intent are considered. This paper presents an educational and musically focused perspective of the relationship between the individual and domain-based creative practice. Drawing primarily from musical and audio-visual examples with particular interest in creative disruption of pre-existing elements, creative strategies of appropriation and recycling are explored in the context of music composition and production. Conclusions focus on the interpretation of creativity as essentially a process of recombination and manipulation and highlight how the relationship between artist and field of practice creates unique creative spaces through which new ideas emerge.
    • Conformity, deformity and reformity

      Brown, Michael; Wilson, Chris; University of Derby (Knowledge, Innovation & Enterprise, 2015)
      In any given field of artistic practice, practitioners position themselves—or find themselves positioned—according to interests and allegiances with spe- cific movements, genres, and traditions. Selecting particular frameworks through which to approach the development of new ideas, patterns and ex- pressions, balance is invariably maintained between the desire to contribute towards and connect with a particular set of domain conventions, whilst at the same time developing distinction and recognition as a creative individual. Creativity through the constraints of artistic domain, discipline and style pro- vides a basis for consideration of notions of originality in the context of activ- ity primarily associated with reconfiguration, manipulation and reorganisation of existing elements and ideas. Drawing from postmodern and post- structuralist perspectives in the analysis of modern hybrid art forms and the emergence of virtual creative environments, the transition from traditional artistic practice and notions of craft and creation, to creative spaces in which elements are manipulated, mutated, combined and distorted with often frivo- lous or subversive intent are considered. This chapter presents an educational and musically focused perspective of the relationship between the individual and domain-based creative practice. Drawing primarily from musical and audio-visual examples with particular interest in creative disruption of pre-existing elements, creative strategies of appropriation and recycling are explored in the context of music composition and production. Conclusions focus on the interpretation of creativity as essen- tially a process of recombination and manipulation and highlight how the relationship between artist and field of practice creates unique creative spaces through which new ideas emerge.
    • Creative dynamics: artistic production as a model of creative interaction

      Brown, Michael; Wilson, Chris; University of Derby (Knowledge, Innovation & Enterprise, 2014)
      Defining creativity in musical terms and the extent to which theories of crea- tivity may reflect and inform creative practice within a UK university arts-based college is at the heart of this chapter. Creative thinking in music, particularly with reference to com- mercial application is where the investigation begins; models of collaborative interaction, which is a fundamental preoccupation for undergraduate popular music students, are re- viewed and evaluated highlighting the boundaries within which composers are required to work to attain commercial authenticity. Beyond this, the development of an applicable creativity toolkit is discussed which has the potential to challenge aesthetic sensibilities al- lowing students to transcend the boundaries of the familiar and explore domains less famil- iar. The chapter concludes by validating the benefits of collaborative creative activities par- ticularly with reference to multi-modal interaction and the role of technology.
    • Creativity and authenticity: perspectives of creative value, utility and quality

      Wilson, Chris; Brown, Michael; University of Derby (DAKAM - Eastern Mediterranean Academic Research Center, 2015)
      This paper is written from the perspective of creative practitioners in sound, music and the visual arts teaching in UK higher education. Primarily concerned with the understanding of creativity as a developmental capacity and identifiable and measurable process and outcome, what began initially as a focused discussion about the assessment of creative artefacts developed progressively into a more general analysis of creative value in terms of reception and developmental experience. Recognising the impact of new technologies and the changing conceptions of creative technique and craft, collaboration and origination, and diversification of attendant interpretive meanings inherent with new artistic forms, the study is an attempt to establish a position from which pedagogic practices can be honed and refined to meet the expectations and needs of contemporary practitioners and educational contexts. The objective in any educational experience and any process of artistic creation being to enrich and to effectively inform further development steps, value is therefore a highly diverse and granular commodity, measurable on many different scales, and capable of understanding in many different ways. This is a study of considerations and perspectives and ways of understanding and working with creative value and an attempt to develop a framework through which to base creative decisions as educators and practitioners. Creativity models tend to emphasise utility and originality as the key factors in determining creative value; the wider recognition and impact of the outcomes of creative endeavour preeminent in the interpretation and attribution of quality and significance. Whilst most evident and analytically objectifiable in the study of reception and in the analysis of outcomes, creative practices and processes nevertheless feature more prominently in the interpretation of value in some fields. Whilst the products of the creative practice of artists, musicians and writers retain the centre ground in the discourse of creativity, the authentication of creative endeavour is nevertheless closely connected to the narratives surrounding the inception and development of the work and the security of the connection established between the creative object and the creative originator; the intangible and entirely conceptual matter of attribution and provenance often proving more significant than physical artefact in substantiating at least commercial value in many cases. Investigating the potential for a meaningful definition of ‘authentic creativity’, notions of novelty, ignorance, forgery, fakery, reproduction and patterning, provide a basis for consideration of creativity both as an unstable concept and in parallel as a metaphor for the human condition. Considering the discourse of authenticity and aesthetics, this paper explores different perspectives of creativity as lived experience and positions analysis in the narratives of insight, imagination, and the romanticism of discovery and talent. Introducing an analysis of creativity through a series of conceptual models to illustrate key concepts and ideas, this essay presents a discussion rooted in a context of collapsing distinctions between the natural and the artificial, the authentic and the inauthentic, the original and the copy, and develops a tentative definition of authentic creativity and creative authenticity for wider consideration. That creativity matters in education and society is widely acknowledged and appreciated. This paper argues for a greater focus on the lived experience of creativity and the significance of determining value in terms of human experience over productivity.
    • Distance coding and performance of the mark 5 and st350 SoundField microphones and their suitability for Ambisonic reproduction.

      Wiggins, Bruce; Spenceley, Thomas; University of Derby (Institute of Acoustics, 2009-11-19)
      Capturing and replaying distance cues for multi-channel audio is currently an under-explored and under-exploited area. Panners that successfully give control of distance do not, currently exist. However, recordings made with 1st order ambisonic, Soundfield microphones replayed over an ambisonic rig can give realistic results with respect to distance perception (particularly when bringing sound sources inside the speaker array). Near-field effect, resulting from the wave front curvature of near-field sources, is one cue recorded by the microphone, but not reproduced by software or hardware panners. Papers by Daniel (2003, 2004) discuss the encoding and decoding of ambisonic material with particular reference to higher-order ambisonics, and describe ‘near-field coding’ filters which encode near-field effect while pre-compensating for finite loudspeaker reproduction distance. While existing research concentrates on its simulation, this report documents an investigation into near-field effect in Soundfield ST350 and MK V tetrahedral microphones. It is found that, as a result of calibration for a flat frequency response at a practical source distance, the Soundfield microphone responses bear strong similarity to various near-field coding filters, suggesting the existence of an optimum loudspeaker array radius for positional localisation. On determination of this distance, recordings may be adapted for proper reproduction at any chosen reference distance using the WigWare ambisonic plug-ins created at the University of Derby.
    • Extending realities: creativity, artistry and technology

      Wilson, Chris; Brown, Michael; University of Derby (KIE, 2013-09-10)
    • The GASP Project

      Werner, Duncan; Uiversity of Derby, Creative Technologies Research Group (2014-06)
      Overview of GASP (Guitars with Ambisonic Spatial Production) presentation
    • GASP: Guitars with ambisonic spatial performance

      Werner, Duncan; Wiggins, Bruce; Lawson, Tom; Weightman, Tom; Callister, Joe; University of Derby: Creative Technologies Research Group (2015-06)
      ‘Guitars with Ambisonic Spatial Performance’ (GASP) is an ongoing project where our expertise in surround sound algorithmic research is combined with off-the-shelf hardware and bespoke software to create a spatial multichannel surround guitar performance system. This poster was funded through the ‘Undergraduate Research Scholarship Scheme’ (URSS) and presented at the University of Derby Buxton Campus 10th Annual Learning & Teaching conference on Wednesday 1st July 2015. The theme being ‘Students as Partners: Linking Teaching, Research and Enterprise’. The poster was also utilised as a contribution to the Creative Technologies Research Group (CTRG) ‘Sounds in Space’ symposium held at the University of Derby in June 2015, at which three pieces of multichannel guitar recordings were demonstrated.
    • The generation of panning laws for irregular speaker arrays using heuristic methods

      Wiggins, Bruce; University of Derby (Audio Engineering Society, 2007-06-25)
      Currently, the ITU standard surround sound speaker arrangement is based on an irregular 5 speaker array. However, this may change to an irregular 7 speaker array (as is now the standard on computer hardware) or more in the future. The Ambisonic system, pioneered by Micheal Gerzon, among others, in the late 1960’s, is very well suited to situations where the end system speaker configuration is not fixed in terms of number or position while also offering a simple way (via energy and velocity vector analysis) of quantifying the performance of such systems. However, while the derivation of the decoders is well documented for regular speaker arrangements [1], optimising the decoders for irregular layouts is not a simple task, where optimisation requires the solution of a set of non linear simultaneous equations, complicated further by the fact that multiple solutions are possible [2]. Craven [3] extended the system to use higher order circular harmonics and presented a 4th order Ambisonic decoder (9 input channels), although the derivation method used was not presented. In this paper a semi-automated decoder optimisation system using heuristic methods will be presented that will be shown to be robust enough to generate higher order Ambisonic decoders based on the energy and velocity vector parameters. This method is then analytically compared to Craven’s decoder using both energy/velocity vector and head related transfer function based methods.
    • Has Ambisonics come of age?

      Wiggins, Bruce; University of Derby (Institute of Acoustics, 2008-11)
      Ambisonics was developed in the 1970’s as a flexible, psycho-acoustically aware system1. Developed at the same time as Quadraphonics2, Ambisonics is an often mis-understood system that was far ahead of it’s time. Due to the ubiquity of surround sound equipment in modern computers and interest in live surround events becoming more widespread, is the time, finally, right for Ambisonics to come into its’ own? In this paper, the definition of what makes a system Ambisonic is clarified with reference made to the traditional energy and velocity vector theory, higher order systems and use in both the live and domestic environment. More recent developments by the author are discussed with respect to irregular Ambisonic decoder design (such as for the ITU 5.1 speaker array) and analysis using Head Related Transfer Function data showing the extra insight this can give into the performance of one, seemingly similar, decoder design over another. The freely available suite of VST plug-ins (comprising of decoders, panners and an Ambisonic reverb) created using this technology are also presented, with case studies of their use in student projects at the University of Derby.
    • A hybrid virtual bass system for optimized steady-state and transient performance

      Hill, Adam J.; Hawksford, Malcolm O. J.; University of Essex (IEEE, 2010-09)
      Bandwidth extension of a constrained loudspeaker system is regularly achieved employing nonlinear bass synthesis. The method operates on the doctrine of the missing fundamental whereby humans infer the presence of a fundamental tone when presented with a signal consisting of higher harmonics of said tone. Nonlinear devices and phase vocoders are commonly used for signal generation; both exhibiting deficiencies. A system is proposed where the two approaches are used in tandem via a mixing algorithm to suppress these deficiencies. Mixing is performed by signal transient content analysis in the frequency domain using constant-Q transforms. The hybrid approach is rated subjectively against various nonlinear device and phase vocoder techniques using the MUSHRA test method.
    • Individualized low-frequency response manipulation for multiple listeners using chameleon subwoofer arrays

      Hill, Adam J.; Hawksford, Malcolm O. J.; University of Essex (IEEE, 2011-07)
      Low-frequency acoustical responses are naturally position dependent across wide listening areas. This is predominantly due to room modes in small, closed spaces. Numerous methodologies have been proposed targeting room mode compensation to give an objectively even response across all listening locations. These techniques cannot guarantee, however, that every listener receives an equally pleasing subjective response. Chameleon subwoofer arrays (CSA) were originally developed to minimize low-frequency spatiotemporal variations by addressing frequency response errors at multiple listening locations using a subwoofer system consisting of multiple degrees of freedom. The CSA system can alternatively be utilized to control listening locations independently, allowing each listener to adjust their localized low-frequency response to their liking. This alternate CSA implementation is evaluated using a bespoke finite-difference time-domain (FDTD) algorithm for small home theater applications.
    • An investigation into the real-time manipulation and control of three-dimensional sound fields

      Wiggins, Bruce; University of Derby (University of Derby, 2004)
      This thesis describes a system that can be used for the decoding of a three dimensional audio recording over headphones or two, or more, speakers. A literature review of psychoacoustics and a review (both historical and current) of surround sound systems is carried out. The need for a system which is platform independent is discussed, and the proposal for a system based on an amalgamation of Ambisonics, binaural and transaural reproduction schemes is given. In order for this system to function optimally, each of the three systems rely on providing the listener with the relevant psychoacoustic cues. The conversion from a five speaker ITU array to binaural decode is well documented but pair-wise panning algorithms will not produce the correct lateralisation parameters at the ears of a centrally seated listener. Although Ambisonics has been well researched, no one has, as yet, produced a psychoacoustically optimised decoder for the standard irregular five speaker array as specified by the ITU as the original theory, as proposed by Gerzon and Barton (1992) was produced (known as a Vienna decoder), and example solutions given, before the standard had been decided on. In this work, the original work by Gerzon and Barton (1992) is analysed, and shown to be suboptimal, showing a high/low frequency decoder mismatch due to the method of solving the set of non-linear simultaneous equations. A method, based on the Tabu search algorithm, is applied to the Vienna decoder problem and is shown to provide superior results to those shown by Gerzon and Barton (1992) and is capable of producing multiple solutions to the Vienna decoder problem. During the write up of this report Craven (2003) has shown how 4th order circular harmonics (as used in Ambisonics) can be used to create a frequency independent panning law for the five speaker ITU array, and this report also shows how the Tabu search algorithm can be used to optimise these decoders further. A new method is then demonstrated using the Tabu search algorithm coupled with lateralisation parameters extracted from a binaural simulation of the Ambisonic system to be optimised (as these are the parameters that the Vienna system is approximating). This method can then be altered to take into account head rotations directly which have been shown as an important psychoacoustic parameter in the localisation of a sound source (Spikofski et al., 2001) and is also shown to be useful in differentiating between decoders optimised using the Tabu search form of the Vienna optimisations as no objective measure had been suggested. Optimisations for both Binaural and Transaural reproductions are then discussed so as to maximise the performance of generic HRTF data (i.e. not individualised) using inverse filtering methods, and a technique is shown that minimises the amount of frequency dependant regularisation needed when calculating cross-talk cancellation filters.
    • Kick-Drum signal acquisition, isolation and reinforcement optimization in live sound

      Hill, Adam J.; Hawksford, Malcolm O. J.; Rosenthal, Adam P.; Gand, Gary; University of Essex; Gand Concert Sound (Audio Engineering Society, 2011-05)
      A critical requirement for popular music in live-sound applications is the achievement of a robust kick-drum sound presented to the audience and the drummer while simultaneously achieving a workable degree of acoustic isolation for other on-stage musicians. Routinely a transparent wall is placed in parallel to the kick-drum heads to attenuate sound from the drummer’s monitor loudspeakers, although this can cause sound quality impairment from comb filter interference. Practical optimization techniques are explored, embracing microphone selection and placement (including multiple microphones in combination), isolation-wall location, drum-monitor electronic delay and echo cancellation. A system analysis is presented augmented by real-world measurements and relevant simulations using a bespoke Finite-Difference Time-Domain (FDTD) algorithm.