An audio-visual system for object-based audio : from recording to listening

Object-based audio is an emerging representation for audio content, where content is represented in a reproduction format-agnostic way and, thus, produced once for consumption on many different kinds of devices. This affords new opportunities for immersive, personalized, and interactive listening experiences. This paper introduces an end-to-end object-based spatial audio pipeline, from sound recording to listening. A high-level system architecture is proposed, which includes novel audiovisual interfaces to support object-based capture and listenertracked rendering, and incorporates a proposed component for objectification, that is, recording content directly into an object-based form. Text-based and extensible metadata enable communication between the system components. An open architecture for object rendering is also proposed. The system’s capabilities are evaluated in two parts. First, listener-tracked reproduction of metadata automatically estimated from two moving talkers is evaluated using an objective binaural localization model. Second, object-based scene capture with audio extracted using blind source separation (to remix between two talkers) and beamforming (to remix a recording of a jazz group) is evaluate

Sparse ℓ1-Optimal Multiloudspeaker Panning and Its Relation to Vector Base Amplitude Panning

Panning techniques, such as vector base amplitude panning (VBAP) are a widely-used practical approach for spatial sound reproduction using multiple loudspeakers. Although limited to a relatively small listening area, they are very efficient and offer good localisation accuracy, timbral quality as well as a graceful degradation of quality outside the sweet spot. The aim of this paper is to investigate optimal sound reproduction techniques that adopt some of the advantageous properties of VBAP, such as the sparsity and the locality of the active loudspeakers for the reproduction of a single audio object. To this end, we state the task of multi-loudspeaker panning as an `1 optimization problem. We demonstrate and prove that the resulting solutions are exactly sparse. Moreover, we show the effect of adding a nonnegativity constraint on the loudspeaker gains in order to preserve the locality of the panning solution. Adding this constraint, `1- optimal panning can be formulated as a linear program. Using this representation, we prove that unique `1-optimal panning solutions incorporating a nonnegativity constraint are identical to VBAP using a Delaunay triangulation for the loudspeaker setup. Using results from linear programming and duality theory, we describe properties and special cases, such as solution ambiguity, of the VBAP solution

Optimization-Based Reproduction of Diffuse Audio Objects

Computer programming, written by the creators of the dataset.Matlab code and generated filter coefficients accompanying a research paper of this same title. Paper abstract: The creation of a diffuse sound event from a single audio signal is an important signal processing task, for instance in spatial audio reproduction or audio coding. Current algorithms based on decorrelation filters or frequency-dependent panning typically cause artefacts due to transients or time-domain aliasing. In this paper, we propose an optimization-based approach to diffusion that creates a set of filters to approximate a desired distribution of frequency-dependent propagation directions to create the perception of a diffuse sound field with a multi-channel audio system. Thus, the diffusion can be optimally adapted to a specific reproduction scenario. In addition, the transient response can be purposefully improved by imposing constraints on the time-domain filter coefficients. | Version:

Object-Based Audio Reproduction using a Listener-Position Adaptive Stereo System

This work introduces a listener-position adaptive stereo reproduction system 10 that allows for the reproduction of 2D object-based audio and for a more accurate 11 localisation when the listener is located outside the sweet spot. The adaptation is 12 composed of two parts; a compensation system that updates the loudspeakers feeds 13 so that the loudspeaker input signals are delivered to the listener with the same 14 magnitude and phase independently of the listening position, as it would occur in 15 a symmetric listening configuration, and an object-based rendering system using 16 conventional panning algorithms. Robustness simulations show that an accurate 17 localisation is possible when the audio objects are panned in the angle seen between 18 the listener and the two loudspeakers. This has been further assessed by objective 19 and subjective localisation experiment

L'immigration au Brésil.

C. P. L'immigration au Brésil. In: Journal de la Société des Américanistes. Tome 16, 1924. pp. 447-448

Acoustic source localization with microphone arrays for remote noise monitoring in an Intensive Care Unit

An approach is described to apply spatial filtering with microphone arrays to localize acoustic sources in an Intensive Care Unit (ICU). This is done to obtain more detailed information about disturbing noise sources in the ICU with the ultimate goal of facilitating the reduction of the overall background noise level, which could potentially improve the patients’ experience and reduce the time needed for recovery. This paper gives a practical description of the system, including the audio hardware setup as well as the design choices for the microphone arrays. Additionally, the necessary signal processing steps required to produce meaningful data are explained, focusing on a novel clustering approach that enables an automatic evaluation of the spatial filtering results. This approach allows the data to be presented to the nursing staff in a way that enables them to act on the results produced by the system

A Listener Position Adaptive Stereo System for Object-Based Reproduction

Stereo reproduction of spatial audio allows the creation of stable acoustic images when the listener is placed in the sweet spot, a small region in the vicinity of the axis of symmetry between both loudspeakers. If the listener moves slightly towards one of the sources, however, the images collapse to the loudspeaker the listener is leaning to. In order to overcome such limitation, a stereo reproduction technique that adapts the sweet spot to the listener position is presented here. This strategy introduces a new approach that maximizes listener immersion by rendering object-based audio, in which several audio objects or sources are placed at virtual locations between the stereo span. By using a video tracking device, the listener is allowed to move freely between the loudspeaker span, while loudspeaker outputs are compensated using conventional panning algorithms so that the position of the different audio objects is kept independent from that of the listener