scholarly journals Sound Propagation and Reconstruction Algorithm Based on Geometry

2019 ◽  
Vol 15 (13) ◽  
pp. 86
Author(s):  
Jihun Park
Keyword(s):  
Virtual Reality ◽  
Physical Environment ◽  
Sound Propagation ◽  
Sound Field ◽  
Reconstruction Algorithm ◽  
Computation Method ◽  
Sound Sources ◽  
3 Dimensional ◽  
Sound Effects ◽  
Sound Theory

This paper presents a method of simulating sound propagation and reconstruction for the virtual reality applications. The algorithm being developed in this paper is based on a ray sound theory. If we are given 3 dimensional geometry input as well as sound sources as inputs, we can compute sound effects over the entire boundary surfaces. In this paper, we present two approaches to compute sound field: The first approach, called forward tracing, traces sounds emanating from sound sources, while the second approach, called geometry based computation, computes possible propagation routes between sources and receivers. We compare two approaches and propose a geometry-based sound computation method for outdoor simulation. This approach is computationally more efficient than the forward sound tracing. The physical environment affects sound propagation simulation by impulse- response. When a sound source waveform and numerically computed impulse in time is convoluted, a synthetic sound is generated. This technique can be easily generalized to synthesize realistic stereo sounds for the virtual reality applications. At the same time, the simulation result can be visualized using VRML.

scholarly journals Ambisonics Sound Source Localization With Varying Amount of Visual Information in Virtual Reality

2021 ◽  
Vol 2 ◽  
Author(s):  
Thirsa Huisman ◽  
Axel Ahrens ◽  
Ewen MacDonald
Keyword(s):  
Virtual Reality ◽  
Visual Information ◽  
Right Hemisphere ◽  
Sound Field ◽  
Auditory Stimuli ◽  
Spatial Cues ◽  
Sound Sources ◽  
Acoustic Localization ◽  
Localization Performance ◽  
The Right

To reproduce realistic audio-visual scenarios in the laboratory, Ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, Ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st-, 3rd-, 5th- or 11th-order Ambisonics with and without visual information. Results showed that with 1st-order Ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small. The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the Ambisonics order, there was no interaction between the Ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using Ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of the auditory stimuli.

scholarly journals Frequency-dependent variation in the two-dimensional beam pattern of an echolocating dolphin

2011 ◽  
Vol 7 (6) ◽  
pp. 836-839 ◽  
Author(s):  
Josefin Starkhammar ◽  
Patrick W. Moore ◽  
Lois Talmadge ◽  
Dorian S. Houser
Keyword(s):  
Sound Propagation ◽  
Sound Field ◽  
Spatial Separation ◽  
Acoustic Properties ◽  
Maximum Pressure ◽  
Frequency Bandwidth ◽  
Sound Sources ◽  
Pressure Peak ◽  
Prey Localization ◽  
Dominant Peak

Recent recordings of dolphin echolocation using a dense array of hydrophones suggest that the echolocation beam is dynamic and can at times consist of a single dominant peak, while at other times it consists of forward projected primary and secondary peaks with similar energy, partially overlapping in space and frequency bandwidth. The spatial separation of the peaks provides an area in front of the dolphin, where the spectral magnitude slopes drop off quickly for certain frequency bands. This region is potentially used to optimize prey localization by directing the maximum pressure slope of the echolocation beam at the target, rather than the maximum pressure peak. The dolphin was able to steer the beam horizontally to a greater extent than previously described. The complex and dynamic sound field generated by the echolocating dolphin may be due to the use of two sets of phonic lips as sound sources, or an unknown complexity in the sound propagation paths or acoustic properties of the forehead tissues of the dolphin.

scholarly journals IDENTIFIKACIJA ZVUČNIH IMPULSA KOD FRIŽIDERA ZA UPOTREBU U DOMAĆINSTVU

2018 ◽  
pp. 115
Author(s):  
Nikola Holecek ◽  
Dejan Dren
Keyword(s):  
Measurement Method ◽  
Sound Field ◽  
Visualization Method ◽  
Acoustic Measurements ◽  
Sound Sources ◽  
Complex Sound ◽  
Sound Effects ◽  
Different Types ◽  
Thermal Dilatation ◽  
The Individual

This paper presents a new visualization method of complex sound sources in combined fridge freezers. Measurement method with sixty array microphones in free sound field conditions is used. Laboratory acoustic measurements using an algorithm of the complex sound sources visualization are performed. With this method, sound effects are successfully identified, localized and calculated. The individual crack noises emitted as a result of thermal dilatation of different types of material in the transitional cooling modes of the household refrigerator.

scholarly journals Sound source localization in virtual reality with ambisonics sound reproduction

2021 ◽  
Author(s):  
Thirsa Huisman ◽  
Axel Ahrens ◽  
Ewen MacDonald
Keyword(s):  
Virtual Reality ◽  
Visual Information ◽  
Right Hemisphere ◽  
Sound Field ◽  
Auditory Stimuli ◽  
Spatial Cues ◽  
Sound Sources ◽  
Acoustic Localization ◽  
Sound Reproduction ◽  
The Right

To reproduce realistic audio-visual scenarios in the laboratory, ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st, 3rd, 5th or 11th order ambisonics with and without visual information. Results showed that with 1st order ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small.The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the ambisonics order, there was no interaction between the ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of auditory stimuli.

scholarly journals 2.5D Sound Field Reproduction Using Higher Order Loudspeakers

2015 ◽  
Vol 15 (6) ◽  
pp. 5-15 ◽  
Author(s):  
Maoshen Jia ◽  
Wenbei Wang ◽  
Ziyu Yang
Keyword(s):  
Least Squares Method ◽  
Sound Field ◽  
Addition Theorem ◽  
Circular Array ◽  
Sound Sources ◽  
3 Dimensional ◽  
Secondary Sources ◽  
3D Sound ◽  
Minimum Number ◽  
Broad Interest

Abstract Using 3-Dimensional (3D) sound sources as secondary sources to 2-Dimensional (2D) sound field reproduction, it is termed 2.5-Dimensional (2.5D) sound field reproduction which is currently drawing broad interest in acoustic signal processing. In this paper we propose a method to reproduce a 2D sound field, using a circular array of 3D High Order (HO) loudspeakers, which provides a mode matching solution based on 3D wave field translation. Using the spherical addition theorem, we first obtain a spherical harmonics representation of a 2D sound field reproduced by an array of HO loudspeakers. Then, the corresponding relationship between the reproduced sound field and the desired sound field is established by spherical/cylindrical harmonic expansions. Finally, the modal weights of HO loudspeakers are designed by using a least squares method. Simulation results show that the proposed method extends the reproduction region and significantly reduces the required minimum number of loudspeakers over the other referenced methods.

scholarly journals Research of Space Positioning Method Based on Sound Field HBT Interference

2018 ◽  
Vol 232 ◽  
pp. 04028
Author(s):  
Jing Zou ◽  
Lei Nie ◽  
Mengran Liu ◽  
Chuankai Jiang
Keyword(s):  
Source Localization ◽  
Sound Source ◽  
Target Location ◽  
Sound Propagation ◽  
Sound Field ◽  
Long Distance ◽  
Sound Sources ◽  
Positioning Method ◽  
New Ideas ◽  
Propagation Media

Based on Hanbury Brown-Twiss (HBT) interference in the sound field, a space positioning method is presented to realize the long-distance and high-precision positioning of sound sources in media. Firstly, theoretical model of HBT interference positioning is established. Location of the sound source can be acquired by analyzing the correlation function of the output signals. Then, sound source localization under different signal-to-noise ratios (SNR) shows that by this method, the sound source can be accurately found with six sensors (two arrays) even the SNR is low to 0.04. Positioning experiment in air is carried out, and the experimental results show that the sound source can be accurately located at 42 meters, and the positioning error is low to 0.1 meters. Thus the validity and accuracy of the HBT interference space location principle is demonstrated. It provides new ideas for the research of long-range target location in sound propagation media (air, water, etc.).

scholarly journals Multi-Detailed 3D Architectural Framework for Sound Perception Research in Virtual Reality

2021 ◽  
Vol 7 ◽  
Author(s):  
Josep Llorca-Bofí ◽  
Michael Vorländer
Keyword(s):  
Virtual Reality ◽  
3D Modeling ◽  
Architectural Design ◽  
Sound Propagation ◽  
Sound Sources ◽  
Sound Perception ◽  
Levels Of Detail ◽  
Modular Concept ◽  
Physically Based ◽  
Architectural Framework

The presentation of architectural design in simulation environments demands strong 3D modeling abilities. Architects usually demonstrate presentation skills that mostly address researchers in the building simulation field. However, there is still a gap between the architect’s deliverable and the contextual scenario for overarching research purposes, mainly caused by the lack of knowledge in the areas where research disciplines overlap. This dilemma is particularly present in the practice of 3D modeling for sound perception research in virtual reality since the building modelers must also gather diverse pieces of knowledge into a contained scenario: ranging from sound sources, sound propagation models to physically based material models. Grounded on this need, this article presents a comprehensive framework, defined by the visual and acoustic cues—geometries, materials, sources, receivers, and postprocessing—on one side and three levels of detail on the other. In this way, very specific research application needs can be covered, as well as a modular concept for future modeling demands. The interconnection between every model element is particularly designed, enabling the assembly among different modalities at different levels of detail. Finally, it provides targeted modeling strategies for architects, depicted in one indoor and one outdoor demonstration for auditory-visual research.

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

scholarly journals Revealing Hidden Local Cultural Heritage through a Serious Escape Game in Outdoor Settings

Information ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Stavroula Tzima ◽  
Georgios Styliaras ◽  
Athanasios Bassounas
Keyword(s):  
Virtual Reality ◽  
Augmented Reality ◽  
Cultural Heritage ◽  
Physical Environment ◽  
Local History ◽  
Educational Context ◽  
Virtual Reality Technology ◽  
The Real ◽  
Hybrid Type ◽  
Game Mechanics

Escape Rooms are presently considered a very popular social entertainment activity, with increasing popularity in education field, since they are considered capable of stimulating the interest of players/students and enhancing learning. The combined game mechanics have led to blended forms of Escape Rooms, the Serious Escape Games (SEGs) and the hybrid type of Escape Rooms that uses Augmented Reality (AR)/Virtual Reality technology, a type that is expected to be widely used in the future. In the current study, the MillSecret is presented, a multi-player Serious Escape Game about local cultural heritage, where the players must solve a riddle about the cultural asset of watermills. MillSecret uses AR technology and it was designed to be conducted in the real-physical environment and in an informal educational context. The paper describes the game, its implementation, the playing process, and its evaluation, which aimed to study the feasibility of game conduction in outdoor settings and the views and experience of players with the game, the local cultural heritage and local history. Evaluation results reveal, among other findings, a very positive first feedback from players that allows us to further evolve the development of the game.

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