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CONFERENCE REPORT 55 th International Conference Spatial Audio Chair: Lauri Savioja 27 –29 August 2014 Helsinki, Finland CONFERENCE REPORT 788 J. Audio Eng. Soc., Vol. 62, No. 11, 2014 November CONFERENCE REPORT Sponsors t the end of August 2014, the Audio Engineering Society was welcomed back to Helsinki for the 55th Conference. It was the sixth AES conference Ato be held in Finland, and the topic was also an AES staple: spatial audio. There have been seven conferences directly concerned with spatial audio and no doubt many more related sessions, workshops, and tutorials at other events. The conference brought together a diverse range of audio scientists from academia and industry (with a 50% split between the two), with interests ranging from the technical reproduction of sound fields, perceptual evaluation, product/service design, musical performance, and more. The wide range of participants (130 attendees from 25 countries) helped to foster a positive atmosphere of discus - sion, ideation, and collaboration. The conference took place in the Helsinki Music Centre, which opened in 2011 and is shared by the Sibelius Academy, the Finnish Radio Symphony Orchestra, and the Helsinki Philharmonic Orchestra. The Centre contains a range of per - formance spaces (the main auditorium was designed by Yasuhisa Toyota and seats 1,700), rehearsal rooms, and recording studios. J. Audio Eng. Soc., Vol. 62, No. 11, 2014 November 789 CONFERENCE REPORT coding) system, which analyzes and separates directional informa - tion and diffuse sound across frequency bands and uses this infor - mation in the resynthesis of spatial sound. Pulkki talked about vari - ous problems that had been encountered and the resulting solutions that were implemented in order to improve the performance of the system. The engineering work on DirAC was complemented by per - ceptual investigation of aspects such as the perception of spatially- wide sources and the relationship between audio and video spatial field width. Following this talk, participants were divided into groups and shown around eight demonstrations in the impressive acoustics facilities at Aalto University. Demos included an immersive audio- visual environment for teleconferencing with 226-degree-horizon - tal-field-of-view video and 3D audio using DirAC, 12-channel auralizations of concert halls and studio control rooms, and a head- tracked Oculus Rift AV experience, among other examples of tech - nical aspects of the DirAC system. The afternoon was rounded off with a talk by Tapio Lokki who detailed his work on the evaluation of concert hall acoustics, Members of the AES 55th Conference organizing committee: from left, considering the mapping between physical factors, sensory evalua - Julia Turku, Ville Pulkki, Tapio Lokki, Lauri Savioja, Andrew Goldberg, and Teemu Koski tion, and preference. The talk provided an interesting overview of sensory evaluation methods, which are often borrowed from food The conference organizing committee should be commended for and wine science and can include individual assessors developing hosting such a successful and engaging event, curating an enter - their own descriptive vocabulary with the use of advanced statisti - taining program of technical and social events. The conference was cal methodologies to assess the relationship between physical chaired by Lauri Savioja, Ville Pulkki compiled the technical parameters, perceptual ratings, and the assessors. Lokki also gave program, Tapio Lokki acted as papers chair, Teemu Koski was the an interesting description of his tour of European concert halls in secretary, Andrew Goldberg organized sponsorship, Julia Turku was order to capture room impulse responses: “we stole the acoustics, treasurer, Kalev Tiits was in charge of the venue, and Florian packed it, and put it in a bus.” Camerer helped to organize the panels. KEYNOTE SEMINARS AND DEMONSTRATIONS LECTURES AT AALTO UNIVERSITY Each of the three days of Proceedings started a day before the conference as 85 participants the conference started were treated to an extra afternoon of tutorials and demonstrations with an invited presenta - hosted by the acoustics group at Aalto University. Ville Pulkki tion from a distinguished opened the event with a talk about psychoacoustics and technolo - researcher in the field, gies of spatial sound. The presentation was intended to offer some carefully selected by the conclusions and output at the culmination of a five-year project that organizing committee to had recently finished. The talk focused on the relationship between cover the engineering, engineering and psychoacoustics, bridging the gap between spatial perceptual, and musical sound technology and psychophysics. Pulkki’s group was tasked aspects of spatial sound with creating a flexible and loudspeaker-agnostic generic audio for - technologies. mat: this was the motivation behind the “DirAC” (directional audio On day one, Sascha Spors gave a talk entitled “The Adventure of Spatial Sound Sascha Spors identifies some key areas Reproduction,” which of spatial audio during his keynote was the perfect way to lecture. kick off the conference. The talk included an outline of the history of spatial audio repro - duction, starting with the invention of the telephone in 1861 all the way through to modern multichannel systems and panning algorithms. Sascha touched upon a number of points that would be revisited in presentations throughout the conference: the fact that it is often necessary to create the desired impression rather than to exactly duplicate a real listening experience; the fact that it is important not to overlook timbral factors in a spatial audio system; and the relationships between signal processing, perception, and acoustics, which when integrated give a complete view of spatial Sakari Tervo presents a demonstration of auralizations of concert halls and studio control rooms in the largest of three anechoic chambers at sound reproduction. During the questions after the talk partici - Aalto University. pants were introduced to the “Catchbox,” a throwable microphone 790 J. Audio Eng. Soc., Vol. 62, No. 11, 2014 November CONFERENCE REPORT that made it rela - The three invited tively easy for the presentations served as a microphone to be good background for the moved around to detailed investigations of auditorium, as well the substantial paper and as providing a poster program, which source of entertain - featured 24 presentations ment as the soft and 16 posters. box was flung across the room. SPATIAL SOUND Jonty Harrison’s MorrowSound ran a 3D audio-visual demo TECHNIQUES over Occulus Rift during the conference. keynote talk on the Day one of the confer - second day was a ence featured two paper good example of sessions on spatial sound the diversity of participants and the outlook of the AES. As an techniques,”chaired by Philip Jackson demonstrates his catching “acousmatic” composer (i.e., music that is made in a studio, Sakari Tervo (Aalto skills to ask a question using the Catchbox microphone. performed over loudspeakers, exists only as a recording, and has an University). unlimited sound palette), Harrison described his modus operandi Philippe-Aubert as being flexible, listening based, and not based around prior plan - Gauthier from the University of Sherbrooke spoke about the benefits ning, and suggested that audio engineering can facilitate this of accurate simulation of spatial sound fields when investigating approach (for example, such composition is only possible due to safety in industrial environments and the need for nondisruptive the development of sound recording and storage). Harrison intro - methods for capturing such environments. He introduced a combi - duced the loudspeaker layouts used in the Birmingham BEAST nation of spot microphones and microphone arrays that were used to (Birmingham ElectroAcoustic Sound Studio) project, which has separate foreground and background sounds. Simulation results over one hundred loudspeakers at its disposal for composition and were promising and the work was due to be continued with real performance. It was interesting to note that the motivation for recordings reproduced over wave field synthesis (WFS). The follow - loudspeaker positioning was empirical and listening-based, and ing paper, presented by Symeon Delikaris-Manias of Aalto University, that in this particular use of spatial sound technology, it was also considered a method for separating acoustic sources, introduc - important to create the sensation of space and movement rather ing modifications to the cross pattern coherence algorithm than extreme accuracy of spatial audio field reproduction. (CroPaC), which had been demonstrated at Aalto the previous day. The final invited presentation was given by Piotr Majdak, who The next two papers concentrated on methods for reproducing sound spoke about “sound localization beyond the horizontal plane.” fields. Philip Coleman (University of Surrey) introduced planarity Majdak spoke about localization mechanisms in humans, starting panning as a way of producing a spatial sound field. This method from the early work by Lord Rayleigh to more modern theories and focuses sound energy on a target zone while also constraining the methods. Binaural methods and head-related transfer functions angle of arrival and was shown to accurately position five virtual (HRTFs) were the subject of much discussion during the confer - loudspeakers. Naomici Yanagidate (Universities of Southampton and ence, particularly the need