Can I trust my ears in VR? Head-related transfer functions and valuation methods with descriptive attributes in virtual reality

In this article, we present the current state of the art in binaural audio with the focus on head-related transfer functions (HRTFs) and valuation methods of virtual acoustics with descriptive attributes. This combination provides a methodology, which delivers the basis for research studies in virtual reality (VR) on individual and non-individual head-related transfer functions. Based on the largely explored localization perception of static audio signals, this review offers an overview of the directional hearing during head and sound source movement and multimodality in audiovisual virtual environments. Perceptual quality characteristics provide evaluation methods from which future HRTF VR experiments and virtual environments studies on binaural acoustics could benefit.

3D sound spatialization with game engines: the virtual acoustics performance of a game engine and a middleware for interactive audio design

This study analyses one of the most popular game engines and an audio middleware to reproduce sound according to sound propagation physics. The analysis focuses on the transmission path between the sound source and the receiver. Even if there are several ready-to-use real-time auralization platforms and software, game engines' use with this aim is a recent study area for acousticians. However, audio design needs with game engines and the limits of their basic releases require additional tools (plugins and middleware) to improve both the quality and realism of sound in virtual environments. The paper discusses the use of Unreal Engine 4 and Wwise's 3D audio production methods in a set of different test environments. It assesses their performance in regard to a commercial geometrical acoustics software. The results show that the investigated version of the game engine and its sound assets are insufficient to simulate real-world cases and that significant improvements can be achieved with use of the middleware.

Instrumentation in Condition of Real and Virtual Acoustics Around Music

Инструментовкой сегодня занимаются не только композиторы, создающие оркестровые партитуры, но и широкий круг музыкантов - профессионалов и любителей, работающих в различных жанрах электронной музыки. Электронная инструментовка имеет много общего с ее традиционным видом, поскольку в обоих случаях решаются одинаковые задачи: реализация колористического потенциала исходного текста, выстраивание композиционной формы с помощью выделения ее разделов, выстраивание фактуры путем заполнения акустического пространства и прорисовки ее пластов. Различия же обусловлены разной природой музыкального материала. В одном случае - это звучание оркестровых инструментов в концертном зале или на открытом воздухе. В другом - это множество синтезированных звуков в условиях виртуальной акустики, которая может быть представлена в самых разных вариантах. Электронная инструментовка, опираясь на сложившиеся в многовековой академической практике приемы, обогащается за счет использования новых звуков и возможностей управления виртуальным пространством их развертывания. Today, not only composers who create orchestral scores are engaged in instrumentation, but also a wide range of musicians-professionals and amateurs working in various genres of electronic music. Electronic instrumentation has a lot in common with its traditional form, since in both cases the same tasks are solved: realizing the color potential of the source text, building a compositional form by highlighting its sections, building a texture by filling the acoustic space and drawing its layers. The differences are due to the different nature of the sound material. In one case, it is the sound of orchestral instruments in a concert hall or in the open air. In the other case, it is a variety of synthesized sounds in a virtual acoustic environment, characterized by diversity and variability. Therefore, electronic instrumentation, based on the techniques developed in centuries-old practice, is enriched by the use of these new sounds and the ability to manage the virtual space of their deployment.

Investigating the Effects of Four Auditory Profiles on Speech Recognition, Overall Quality, and Noise Annoyance With Simulated Hearing-Aid Processing Strategies

Effective hearing aid (HA) rehabilitation requires personalization of the HA fitting parameters, but in current clinical practice only the gain prescription is typically individualized. To optimize the fitting process, advanced HA settings such as noise reduction and microphone directionality can also be tailored to individual hearing deficits. In two earlier studies, an auditory test battery and a data-driven approach that allow classifying hearing-impaired listeners into four auditory profiles were developed. Because these profiles were found to be characterized by markedly different hearing abilities, it was hypothesized that more tailored HA fittings would lead to better outcomes for such listeners. Here, we explored potential interactions between the four auditory profiles and HA outcome as assessed with three different measures (speech recognition, overall quality, and noise annoyance) and six HA processing strategies with various noise reduction, directionality, and compression settings. Using virtual acoustics, a realistic speech-in-noise environment was simulated. The stimuli were generated using a HA simulator and presented to 49 habitual HA users who had previously been profiled. The four auditory profiles differed clearly in terms of their mean aided speech reception thresholds, thereby implying different needs in terms of signal-to-noise ratio improvement. However, no clear interactions with the tested HA processing strategies were found. Overall, these findings suggest that the auditory profiles can capture some of the individual differences in HA processing needs and that further research is required to identify suitable HA solutions for them.

The Performances at the Theatre of the Pythion in Gortyna, Crete. Virtual Acoustics Analysis as a Support for Interpretation

The location of the so-called “small” Roman theatre of Gortyna (Crete), precisely at the back of the temple dedicated to Apollo Pythios, suggests a clear correlation of this monument with religious rituals. We may suppose that the theatre was used in particular during the Ludi Apollinares (Pythia), namely games and a festival dedicated to the God Apollo (held for the first time in Rome in 212 BC) or during the iso-Olympic agones as witnessed by the epigraphic sources of the imperial age. However, we have to consider also the possibility that the “small” theatre of Gortyna could have housed civic ceremonies or other activities related to the life of the Koinon ton Kreton, the federal assembly of all the Cretan cities which had its seat during the imperial times right in the space of the sanctuary. This paper aims to verify the typology of performances and activities that could take place in the theatre of the Pythion (namely if it was more suitable for music or speech) through virtual acoustics analysis. The study of the acoustics’ quality has provided significant support to formulate hypotheses about the primary function of the theatre of the Pythion at Gortyna.