AES New York 2019
Engineering Brief EB6

EB6 - Spatial Audio

Saturday, October 19, 2:00 pm — 3:00 pm

Filippo Maria Fazi, University of Southampton - Southampton, Hampshire, UK

EB6-1 Study of the Effect of Tikhonov Regularization on the Low Frequency Performance of Cross-Talk Cancellation SystemsFilippo Maria Fazi, University of Southampton - Southampton, Hampshire, UK; Eric Hamdan, University of Southampton - Southampton, UK; Marcos Simon, AudioScenic - Southampton UK; University of Southampton - Southampton, UK; Andreas Franck, University of Southampton - Southampton, Hampshire, UK
Tikhonov regularization is widely applied to the design of cross-talk cancellation (CTC) systems to ensure stability by limiting the loudspeaker array effort. The effect of regularization is significant especially at low frequencies, where the underlying inverse system is generally ill-posed. Previous work by the authors demonstrated that regularization leads to a distortion of the auditory scene, known as stage compression. In this work an analytical formula is derived to calculate, for a given loudspeaker arrangement, the minimum amount of Tikhonov regularization required to ensure that the array effort does not exceed the desired limit. The analytical derivation is presented also of the low frequency limit below which the effect of regularization has a significant effect on the CTC system performance. [Presentation only; not available in E-Library]

EB6-2 Subjective Comparison of Binaural Audio Rendering through Headphones and CTCJonathan Phillips, University of Southhampton - Southampton, UK; DELETE Simón, University of Southampton - Southampton, UK
This work compares the subjective performance of a compact cross-talk cancellation (CTC) soundbar prototype compared to headphone reproduction. Preference scores were obtained from listening to different video content with binaural audio. A graphical user interface (GUI) was designed to show the video content, switch between systems and elicit preference scores and ratings of several spatial audio attributes. The study aimed to determine how these two methods compare in terms of relative preference and attribute performance by combining four different video content. Emphasis was placed on the perception of envelopment (or immersion) alongside clarity, depth of field, horizontal width, realism, and spatial naturalness. The results show a preference towards the CTC soundbar over headphones over most of the content/attributes configurations. [Presentation only; not available in E-Library]

EB6-3 Tetra-Speaker: Continual Evaluation of the Immersive Experience of a Single-Point Reproduction SystemParichat Songmuang, New York University - New York, NY, USA
In the first phase of experimentation, a tetra-speaker had been built as an efficient and compact system for the reproduction of individual sound sources. The reproduction process was based on the relationship of a single sound source, such as an instrument, and an acoustic space. This relationship focused on the radiating behavior of the source. In this paper the tetra-speaker is further evaluated in a case-like study on the immersive experience of the system with additional discussion of how the system may expand its usage to improve this experience within virtual environments. Professionals within the audio field were asked to give an expert's opinion based on defined attributes of spatial impression and realism.
Engineering Brief 553

EB6-4 Tetrahedral Microphones: An Effective A/B Main SystemAlexander Dobson, McGill University - Montreal, QC, Canada; Wieslaw Woszczyk, McGill University - Montreal, QC, Canada
A simple approach to produce an effective stereo main audio recording system using tetrahedral microphones is described, capturing a full array of close and distant sound with a substantial amount of early reflections. This allows for the easy possibility of later surround or 3D reproduction. Furthermore, the implementation of a pragmatic and simple two-microphone set-up can lead to an efficient capture of the stereo soundfield that has many applications. Particular attention was paid to binaural mixing of this microphone system to demonstrate an easy first step into immersive reproduction of the sound.
Engineering Brief 554

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