Spatial Perception of Sound Source Distribution in the Median Plane

Trailing-edge serrations have proven to be valid applications of trailing edge noise mitigation for an airfoil, while the physical noise reduction mechanism has not been adequately studied. We performed simulations employing Large-eddy simulation and the Lighthill–Curle method to reveal the variation in the hydrodynamic field and sound source due to the trailing edge serrations. The grid resolution and computational results were validated against experimental data. The simulation results show that: the trailing edge serrations impede the growth of spanwise vortices and promote the development of streamwise vortices near the trailing edge and the wake; the velocity fluctuations in the vertical cross-section of the streamwise direction near the trailing edge are reduced for the serrated airfoil, thereby obviously reducing the strength of the pressure fluctuations near the trailing edge; and the trailing edge serrations decrease the distribution of the sound source near the trailing edge and reduce the local peak value of sound pressure level in a specific frequency range as well as the overall sound pressure level. Moreover, we observed that, in the flow around the NACA0012 airfoil, the location where the strong sound source distribution begins to appear is in good agreement with the location where the separated boundary layer reattaches. It is therefore effective to reduce trailing edge noise by applying serrations on the upstream of the reattachment point.

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Spatial Localization of Concurrent Multiple Sound Sources Using Phase Candidate Histogram

Journal of Advanced Computational Intelligence and Intelligent Informatics ◽

10.20965/jaciii.2011.p1277 ◽

2011 ◽

Vol 15 (9) ◽

pp. 1277-1286

Author(s):

Huakang Li ◽

◽

Jie Huang ◽

Minyi Guo ◽

Qunfei Zhao

Keyword(s):

Sound Source ◽

Real Life ◽

Source Distribution ◽

Precedence Effect ◽

Spherical Robot ◽

Spatial Cues ◽

Sound Sources ◽

Effect Model ◽

Reverberant Environments ◽

Spatial Locations

Mobile robots communicating with people would benefit from being able to detect sound sources to help localize interesting events in real-life settings. We propose using a spherical robot with four microphones to determine the spatial locations of multiple sound sources in ordinary rooms. The arrival temporal disparities from phase difference histograms are used to calculate the time differences. A precedence effect model suppresses the influence of echoes in reverberant environments. To integrate spatial cues of different microphones, we map the correlation between different microphone pairs on a 3D map corresponding to the azimuth and elevation of sound source direction. Results of experiments indicate that our proposed system provides sound source distribution very clearly and precisely, even concurrently in reverberant environments with the Echo Avoidance (EA) model.

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Spatial Perception Under Visual Restriction by Moving a Sound Source Using 3D Audio

Advances in Industrial Design - Lecture Notes in Networks and Systems ◽

10.1007/978-3-030-80829-7_93 ◽

2021 ◽

pp. 757-764

Author(s):

Koki Murakami ◽

Keiichi Watanuki ◽

Kazunori Kaede

Keyword(s):

Sound Source ◽

Spatial Perception ◽

3D Audio

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Human Characteristics of Sound Localization under Masking for the Early Detection of Dementia

Early Detection and Rehabilitation Technologies for Dementia ◽

10.4018/978-1-60960-559-9.ch008 ◽

2011 ◽

pp. 65-71 ◽

Cited By ~ 1

Author(s):

Kouji Nagashima ◽

Jinglong Wu ◽

Satoshi Takahashi

Keyword(s):

Sound Localization ◽

Sound Source ◽

Early Stage ◽

Vertical Plane ◽

Senior Citizen ◽

Median Plane ◽

Young Person ◽

Dementia Patient ◽

Localization Ability ◽

Few Data

Sound localization ability differs among people, such as between a young person, a senior citizen, and a dementia patient. Therefore, it is possible to detect dementia at an early stage by measuring a difference in this ability. Experiments for sound source localization in the horizontal plane show that the ability is improved by separating the presented locations between the signal and a masker. However, there are few data regarding sound localization in the vertical plane. The threshold in the perpendicular plane has been measured, but only experiments in the median plane regarding sound localization have been reported, and its characterization in other aspects has not been clarified. Previous studies about localization ability in the vertical plane have reported contradictory results. One is that the sound source from an upper direction is perceptually superior for a subject, and the other is that a lower direction is superior. The purpose of this study in this chapter is to clarify sound localization ability in the vertical plane and to detect dementia in the early stage using the aging tendency of aural characteristics.

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