Effects of virtual acoustics on dynamic auditory distance perception

Sound propagation encompasses various acoustic phenomena including reverberation. Current virtual acoustic methods, ranging from parametric filters to physically-accurate solvers, can simulate reverberation with varying degrees of fidelity. We investigate the effects of reverberant sounds generated using different propagation algorithms on acoustic distance perception, i.e., how faraway humans perceive a sound source. In particular, we evaluate two classes of methods for real-time sound propagation in dynamic scenes based on parametric filters and ray tracing. Our study shows that the more accurate method shows less distance compression as compared to the approximate, filter-based method. This suggests that accurate reverberation in VR results in a better reproduction of acoustic distances. We also quantify the levels of distance compression introduced by different propagation methods in a virtual environment.Comment: 8 Pages, 7 figure

Validation of a loudspeaker-based room auralization system using speech intelligibility measures

A novel loudspeaker-based room auralization (LoRA) system has been proposed to generate versatile and realistic virtual auditory environments (VAEs) for investigating human auditory perception. This system efficiently combines modern room acoustic models with loudspeaker auralization using either single loudspeaker or high-order Ambisonics (HOA) auralization. The LoRA signal processing of the direct sound and the early reflections was investigated by measuring the speech intelligibility enhancement by early reflections in diffuse background noise. Danish sentences were simulated in a classroom and the direct sound and each early reflection were either auralized with a single loudspeaker, HOA or first-order Ambisonics. Results indicated that (i) absolute intelligibility scores are significantly dependent on the reproduced technique and that (ii) early reflections reproduced with HOA provide a similar benefit on intelligibility as when reproduced with a single loudspeaker. It is concluded that speech intelligibility experiments can be carried out with the LoRA system either with the single loudspeaker or HOA technique.9 page(s

CPX based synthesis for binaural auralization of vehicle rolling noise to an arbitrary positioned stander-by receiver

Virtual reality is becoming an important tool for studying the interaction between pedestrians and road vehicles, by allowing the analysis of potentially hazard situations without placing subjects in real risk. However, most of the current simulators are unable to accurately recreate traffic sounds that are congruent with the visual scene. This has been recognized as a fault in the virtual audio-visual scenarios used in such contexts. This study proposes a method for delivering a binaural auralization of the noise generated by a moving vehicle to an arbitrarily located moving listener (pedestrian). Building on previously developed methods, the proposal presented here integrates in a novel way a dynamic auralization engine, thus enabling real-time update of the acoustic cues in the binaural signal delivered via headphones. Furthermore, the proposed auralization routine uses Close ProXimity (CPX) tyre-road noise signal as sound source input, facilitating the quick interchangeability of source signals, and easing the noise collection procedure. Two validation experiments were carried out, one to quantitatively compare field signals with CPX-derived virtual signal recordings, and another to assess these same signals through psychoacoustic models. The latter aims to assure that the reproduction of the synthesized signal is perceptually similar to one occurring on pedestrian/vehicle interactions during situations of street crossing. Discrepancies were detected, and emphasized when the vehicle is within close distance from the receiver (pedestrian). However, the analysis indicated that these pose no hindrance to the study of vehicle–pedestrian interaction. Improvements to the method are identified and further developments are proposed.This work was supported by the ‘‘Fundação para a Ciência e a Tecnologia” [PTDC/ECM-TRA/3568/2014, SFRH/BD/131638/2017, UIDB/04029/2020] This work is part of the activities of the research project AnPeB – ‘‘ANalysis of PEdestrians Behaviour based on simulated urban environments and its incorporation in risk modelling” (PTDC/ECM TRA/3568/2014), funded by the ‘‘Promover a Produção Científica e Desenvolvimento Tecnológico e a Constituição de Redes Temáti cas” (3599-PPCDT) project and supported by the ‘‘European Com munity Fund FEDER” and the doctoral scholarship SFRH/ BD/131638/2017, funded by ‘‘Fundação para a Ciência e a Tecnolo gia (FCT)”

Spatial Sound Rendering – A Survey

Simulating propagation of sound and audio rendering can improve the sense of realism and the immersion both in complex acoustic environments and dynamic virtual scenes. In studies of sound auralization, the focus has always been on room acoustics modeling, but most of the same methods are also applicable in the construction of virtual environments such as those developed to facilitate computer gaming, cognitive research, and simulated training scenarios. This paper is a review of state-of-the-art techniques that are based on acoustic principles that apply not only to real rooms but also in 3D virtual environments. The paper also highlights the need to expand the field of immersive sound in a web based browsing environment, because, despite the interest and many benefits, few developments seem to have taken place within this context. Moreover, the paper includes a list of the most effective algorithms used for modelling spatial sound propagation and reports their advantages and disadvantages. Finally, the paper emphasizes in the evaluation of these proposed works

Comparing timbre estimation using auditory models with and without hearing loss

We propose a concept for evaluating signal transformations for music signals with respect to an individual hearing deficit by using an auditory model. This deficit is simulated in the model by changing specific model parameters. Our idea is extracting the musical attributes rhythm, pitch, loudness and timbre and comparing the modified model output to the original one. While rhythm, pitch, and loudness estimation are studied in previous works the focus in this paper concentrates on timbre estimation. Results are shown for the original auditory model and three models, each simulating a specific hearing loss

Choosing audio devices on the basis of listeners’ spatial perception: A case study of headphones vs in-earphones

The Earphones and Headphones industry is steadily growing following the emergence of new technological advancements and new applications. New methods to determine listeners’ performance using different types of audio output devices will be in high demand. In this paper we adapt a methodology for evaluation of listeners’ auditory localization accuracy to support the choice between two devices. As a case study, we compare a particular set of in-earphones and headphones. Our goal was to present a method that allowed us to: (1) conclude which audio device provided the most accurate sense of auditory localization; (2) understand the effect of training on task performance; and (3) determine which type of device benefits the most from short sessions of training in auditory localization. Participants had better performances using headphones. Nevertheless, we can reduce the differences between devices if short training sessions are included and the same device is used between training and test.info:eu-repo/semantics/publishedVersio