Proceedings of the EAA Spatial Audio Signal Processing symposium: SASP 2019

International audienc

Border: A Live Performance Based on Web AR and a Gesture-Controlled Virtual Instrument

International audienceRecent technological advances, such as increased CPU/GPU processing speed, along with the miniaturization of devices and sensors, have created new possibilities for integrating immersive technologies in music and performance art. Virtual and Augmented Reality (VR/AR) have become increasingly interesting as mobile device platforms, such as up-to-date smartphones, with necessary CPU resources entered the consumer market. In combination with recent web technologies, any mobile device can simply connect with a browser to a local server to access the latest technology. The web platform also eases the integration of collabora-tive situated media in participatory artwork. In this paper , we present the interactive music improvisation piece 'Border,' premiered in 2018 at the Beyond Festival at the Center for Art and Media Karlsruhe (ZKM). This piece explores the interaction between a performer and the audience using web-based applications-including AR, real-time 3D audio/video streaming, advanced web audio, and gesture-controlled virtual instruments-on smart mobile devices

A 3D real time rendering engine for binaural sound reproduction

Proceedings of the 9th International Conference on Auditory Display (ICAD), Boston, MA, July 7-9, 2003.A method of computationally efficient 3D sound reproduction via headphones is presented using a virtual Ambisonic approach. Previous studies have shown that incorporating head tracking as well as room simulation is important to improve sound source localization capabilities. The simulation of virtual acoustic space requires to filter the stimuli with head related transfer functions (HRTFs). In time-varying systems this yields the problem of high quality interpolation between different HRTFs. The proposed model states that encoding signals into Ambisonic domain results in time-invariant HRTF filters. The proposed system is implemented on a usual notebook using Pure Data (PD), a graphically based open source real time computer music software

Representation of sound fields for audio recording and reproduction

Spherical and circular microphone arrays and loudspeaker arrays are often used for the recording and reproductionof a given sound field. A number of approaches and formats are available for the representation of the recordedfield, some of which are more popular among the audio engineering community (B-format, virtual microphones,etc.) whilst other representations are widely used in the literature on mathematics (generalized Fourier series,single layer potential, Herglotz wave function, etc.). In this paper, some of the properties of the various approachesand some of their differences are discussed. The analysis includes the representation of near-field sources and thechoice of basis functions used for the representation

Orgue : intérieur/extérieur

cote interne IRCAM: Dalessandro12aNone / NoneNational audienceOrgue : intérieur/extérieu

Introduction to the Special Issue on Recent Advances in Ambisonics and Spherical Acoustics

cote interne IRCAM: Noisternig12bNone / NoneNational audienceIntroduction to the Special Issue on Recent Advances in Ambisonics and Spherical Acoustic

Of Pipes and Patches: Listening to augmented pipe organs

International audiencePipe organs are complex timbral synthesisers in an early acousmatic setting, which have always accompanied the evolution of music and technology. The most recent development is digital augmentation: the organ sound is captured, transformed and then played back in real time. The present augmented organ project relies on three main aesthetic principles: microphony, fusion and instrumentality. Micro-phony means that sounds are captured inside the organ case, close to the pipes. Real-time audio effects are then applied to the internal sounds before they are played back over loudspeakers; the transformed sounds interact with the original sounds of the pipe organ. The fusion principle exploits the blending effect of the acoustic space surrounding the instrument ; the room response transforms the sounds of many single-sound sources into a consistent and organ-typical soundscape at the listener's position. The instrumentality principle restricts electroacoustic processing to organ sounds only, excluding non-organ sound sources or samples. This article proposes a taxonomy of musical effects. It discusses aesthetic questions concerning the perceptual fusion of acoustic and electronic sources. Both extended playing techniques and digital audio can create musical gestures that conjoin the heterogeneous sonic worlds of pipe organs and electronics. This results in a paradoxical listening experience of unity in the diversity: the music is at the same time electroacoustic and instrumental

On the decomposition of acoustic source radiation patterns measured with surrounding spherical microphone arrays

cote interne IRCAM: Noisternig11bNone / NoneNational audienceThis article discusses the measurement of acoustic source radiation patterns with surrounding spherical microphone arrays in the context of acoustic holography. For practical reasons the spherical wave spectrum, which forms the basis for spherical holography, is determined through spherical harmonic transform (SHT) of discrete observations on the sphere. The discrete SHT and its limitations are addressed, particularly with emphasis on spherical harmonic order truncation and angular sampling; the existence and kind of spherical harmonic decompositions for different fundamental angular sampling schemes are summarized and compared for a varying number of sampling points. In conclusion, feasible array configurations for accurate acoustic holography are outlined with respect to numerical accuracy and hardware efficiency

Détection et caractérisation des premières réflexions dans des réponses impulsionnelles spatiales par la fonction d'onde de Herglotz

<par> La mesure de réponses impulsionnelles spatiales de salles par des antennes sphériques de microphones permet la reproduction tri-dimensionnelle de l'effet de réverbération de salle par convolution multicanal sur des dispositifs sonores immersifs (``<i>surround-sound</i>''). L'avantage de cette approche est que la réponse impulsionnelle représente l'empreinte acoustique exacte de l'espace mesuré ; cependant, une mesure donnée demeure statique par nature. De plus, l'opération de convolution multicanal est très couteuse en termes de puissance de calcul numérique. Certaines méthodes paramétriques cherchent à contourner ces problèmes en décomposant la réponse impulsionnelle trame par trame en une composante entièrement directionnelle et une autre parfaitement diffuse. Les réverbérateurs hybrides cherchent plutôt à alléger le coût de calcul en reproduisant la queue de réverbération par un réseau de retards bouclés, limitant la convolution aux réflexions précoces. Une analyse de la réponse mesurée permet de modéliser la queue de réverbération tardive ainsi paramétrer correctement le réseau de retards. Les caractéristiques de la réverbération tardive peuvent ensuite être facilement modifiées en manipulant les paramètres du réseau. Une modélisation des premières réflexions permettrait quant à elle de modifier la partie précoce de la réponse, ouvrant ainsi la voie à une manipulation complète de l'effet de réverbération. <par> Dans cette communication, nous proposons une méthode de détection et de caractérisation des premières réflexions basée sur le formalisme de la fonction d'onde de Herglotz. Cette approche est évaluée sur des signaux simulés et comparée à une localisation plus classique par formation de voies. Enfin, des exemples d'application à des mesures réelles sont présentés et une brève discussion est ouverte sur les différentes stratégies de manipulation rendues possibles par ce travail