Bio-Inspired Microscale Three Dimensional Directional Sensing Microphone Array

Direct sound that is captured by the upper layer of a three-dimensional (3D) microphone array is typically regarded as vertical interchannel crosstalk (VIC), since it tends to produce an undesired effect of the sound source image being elevated from the ear-level loudspeaker layer position (0°) in reproduction. The present study examined the effectiveness of band-limited VIC attenuation methods on preventing the vertical image shift problem. In a subjective experiment, five natural sound sources were presented as vertically-oriented phantom images while using two stereophonic loudspeaker pairs elevated at 0° and 30° in front of the listener. The upper layer signal (i.e., VIC) was attenuated in various octave-band-dependent conditions that were based on vertical localisation thresholds obtained from previous studies. The results showed that it was possible to achieve the goal of panning the phantom image at the same height as the image produced by the main loudspeaker layer by attenuating only a single octave band with the centre frequency of 4 kHz or 8 kHz or multiple bands at 1 kHz and above. This has a useful practical implication in 3D sound recording and mixing where a vertically oriented phantom image is rendered.

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Compressive Spherical Beamforming for Acoustic Source Identification

Acta Acustica united with Acustica ◽

10.3813/aaa.919406 ◽

2019 ◽

Vol 105 (6) ◽

pp. 1000-1014

Author(s):

Guoli Ping ◽

Zhigang Chu ◽

Yang Yang

Keyword(s):

Spherical Harmonics ◽

Matching Pursuit ◽

Microphone Array ◽

Angular Position ◽

Three Dimensional ◽

Sparse Recovery ◽

Relative Pressure ◽

Sensing Matrix ◽

Norm Minimization ◽

Acoustic Contribution

This study examines a compressive spherical beamforming (CSB) method, using a rigid spherical microphone array to localize and quantify the acoustic contribution of sources. The method relies on the array signal model in the spherical harmonics domain that can be represented as a spatially sparse problem. This makes it possible to use compressive sensing to solve an underdetermined problem via promoting sparsity. The estimation of the angular position of sources with respect to the microphone array, as well as the three-dimensional localization over a volume are investigated. Several sparse recovery algorithms [orthogonal matching pursuit (OMP), generalized OMP, ϱ1-norm minimization, and reweighted ϱ1-norm minimization] are examined for this purpose. The numerical and experimental results indicate that sparse recovery methods outperform conventional spherical harmonics beamforming. Reweighted ϱ1-norm has good adaptability to noise, improving the robustness of CSB. The method can successfully localize the angular position of sources, and quantify their relative pressure contribution. The method is promising to localize sources in a three-dimensional domain of interest. However, the three-dimensional localization is more sensitive to noise, source distance, and properties of the sensing matrix than the two-dimensional localization.

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A Miniature Four-Microphone Array for Two-Dimensional Direction-of-Arrival Estimation Based on Biomimetic Time-Delay Magnification

Journal of Vibration and Acoustics ◽

10.1115/1.4042124 ◽

2019 ◽

Vol 141 (2) ◽

Cited By ~ 1

Author(s):

Ling Liu ◽

Ming Yang ◽

Yaqiong Zhang ◽

Xinlei Zhu ◽

Na Ta ◽

...

Keyword(s):

Time Delay ◽

Microphone Array ◽

Dimensional Space ◽

Three Dimensional ◽

Coupled System ◽

Direction Of Arrival ◽

Physical Parameters ◽

Two Dimensional ◽

Coupling Algorithm ◽

Three Dimensional Space

A miniature microphone array based on interaural time difference (ITD) is designed. This array contains four microphones with certain arrangement and aims for two-dimensional (azimuth and elevation) direction-of-arrival (DOA) estimation in the whole three-dimensional space. The array can be small because it uses a coupling algorithm that magnifies the time delay between the signals received by every two microphones. The coupling algorithm is built according to a pairwise-coupled multidimensional mechanical model inspired by the ears of the tiny parasitoid fly Ormia ochracea. It was verified that the time-delay magnification can be independent of the incident angle when the parameters in the model satisfy specific relationships. This paper further investigates the multidimensional coupled system and advocates to realize the magnification mechanism in algorithm, where the physical parameters can change according to sound frequency to ensure the time-delay magnification. Moreover, the arrangement of microphones is specially designed to help the array to achieve similar measuring accuracy for all directions in the three-dimensional space. Corresponding signal process procedures are also provided. Simulations that use such an array to estimate the azimuth and elevation angles of sound source are performed via general cross-correlation (GCC) method. Results verify the feasibility of the microphone array and show that the accuracy of the estimation increases after the signals are processed by the coupled system.

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