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Journal articles on the topic 'Directivity'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Nakazawa, Toshiyasu, and Naoaki Shinohara. "Study on aircraft noise directivity of behind the start of takeoff roll." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 3 (2021): 3202–8. http://dx.doi.org/10.3397/in-2021-2330.

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This paper discusses aircraft noise directivity behind the start of takeoff roll. Aircraft noise has the radiation directivity because of aircraft engine mount position and the engine noise directivity. Thus, lateral noise directivity correction is recommended in airport noise calculation guidelines such as ECAC Doc.29 and ICAO Doc9911. In these guidelines, the directivity of flyover noise and the directivity at the start of takeoff roll on ground are prepared separately. A 90-degree dipole model is used for the directivity of the flyover noise, and another similar directivity is used for the

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2

Sun, Xiaofang, Shisong Zhang, and Zhongshan Yao. "Directivity of spherical acoustic scattering based on COMSOL." Journal of Physics: Conference Series 2458, no. 1 (2023): 012030. http://dx.doi.org/10.1088/1742-6596/2458/1/012030.

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Abstract The acoustic scattering characteristics of spheres are the basis for studying the sound scattering law of the target. The directivity of acoustic scattering is one of the most important characteristics of the target sound scattering law. In this paper, the acoustic scattering characteristics of rigid spheres and elastic spherical shells are analyzed from the two typical basic models of the rigid sphere and elastic spherical shell. The sound scattering directivity corresponding to different ka values under different models is analyzed by COMSOL finite element simulation analysis. The c

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3

Trine, Allison, Margaret Miller, Emily Buss, G. Christopher Stecker, and Brian B. Monson. "Speech directivity patterns generated from a high-fidelity speech corpus." Journal of the Acoustical Society of America 153, no. 3_supplement (2023): A292. http://dx.doi.org/10.1121/10.0018894.

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Human talkers are directional sound sources—a phenomenon that has consequences for speech perception in multi-talker environments. Directivity patterns for speech showing frequency- and angle-dependent radiation reveal that speech generally becomes more directional toward the front of the talker as frequency increases. Differences in physical attributes can lead to individual variability in directivity patterns across talkers. Here, we examine individual variability in speech directivity using frequency-dependentdirectivity indices and directivity maps. Speech directivity was examined in the h

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4

Zhao, Guozhu, Kaibo Shi, and Shouming Zhong. "Research on Array Structures of Acoustic Directional Transducer." Mathematical Problems in Engineering 2021 (January 2, 2021): 1–5. http://dx.doi.org/10.1155/2021/6670277.

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This paper focuses on the directivity design of array structures of acoustic directional transducers. Based on Huygens principles, the directivity formula of transducer arrays under random distribution in xyz space is derived when the circular piston transducers are used as the array element, which is used to analyze the directivity and acoustic pressure of conical transducer arrangements. In addition, a practical approach to analyze the directivity and acoustic pressure of transducer arrays under random arrangements is proposed. Findings. The conical transducer arrays show side lobes at highe

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5

Musset, S., M. Maksimovic, E. Kontar, et al. "Simulations of radio-wave anisotropic scattering to interpret type III radio burst data from Solar Orbiter, Parker Solar Probe, STEREO, and Wind." Astronomy & Astrophysics 656 (December 2021): A34. http://dx.doi.org/10.1051/0004-6361/202140998.

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Aims. We use multi-spacecraft observations of individual type III radio bursts to calculate the directivity of the radio emission. We compare these data to the results of ray-tracing simulations of the radio-wave propagation and probe the plasma properties of the inner heliosphere. Methods. We used ray-tracing simulations of radio-wave propagation with anisotropic scattering on density inhomogeneities to study the directivity of radio emissions. Simultaneous observations of type III radio bursts by four widely separated spacecraft were used to calculate the directivity and position of the radi

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6

O'Donoghue, Jennifer L., and Karen R. Strobel. "Directivity and Freedom." American Behavioral Scientist 51, no. 3 (2007): 465–85. http://dx.doi.org/10.1177/0002764207306071.

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7

Dittberner, Andrew B. "Quantifying microphone directivity." Hearing Journal 56, no. 11 (2003): 22. http://dx.doi.org/10.1097/01.hj.0000292901.09293.7b.

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8

Jers, Harald. "Directivity of singers." Journal of the Acoustical Society of America 118, no. 3 (2005): 2008. http://dx.doi.org/10.1121/1.4785700.

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9

Johnston, James David. "Perceptual speaker directivity." Journal of the Acoustical Society of America 120, no. 4 (2006): 1763. http://dx.doi.org/10.1121/1.2372346.

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10

Yatabe, Kohei. "Modeling source directivity by solving inverse problems." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 2 (2023): 6088–91. http://dx.doi.org/10.3397/in_2023_0894.

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Directivity is an important property of a sound source in the real world. Howerver, majority of the wave-based acoustic simulation does not reflect directivity of a source. One of the reasons is that modeling of source directivity is not a simple task and remains a matter of research. In this talk, our attempts of modeling source directivity in time or frequency domains are briefly introduced.

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11

Liu, Hong, and Guo Zhu Zhao. "Two Methods to Test Transducer Array Directivity." Advanced Materials Research 912-914 (April 2014): 1485–88. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.1485.

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An array which possess more array element number and whose frequency of the drive signal can be as large as possible in a range, directivity will be more preferable. On the other hand, when the structure of the sound radiating surface of the transducer or array layout is symmetrical, the corresponding directivity pattern will be symmetrical. In order to test transducer directivity, two methods are designed. The one is to measure the ultrasonic sound pressure level by instruments. The sound pressure level is measured at multiple points to deduce the directivity angle of the acoustic transducer

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12

Du, Bokai, Qun Yan, Ningjuan Dong, Qing Xue, and Yixiao Cheng. "Active noise control with variable directivity loudspeakers." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 6 (2023): 2756–61. http://dx.doi.org/10.3397/in_2023_0401.

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Active noise control (ANC) is an effective way to reduce the low frequency noise level for passengers in cars or aircrafts. In these applications, secondary sources are usually monopole loudspeakers. Variable directivity loudspeaker is a kind of loudspeaker which is able to control its own radiation directivity. It is potential to be able to control the sound field better compared monopole loudspeaker. Inspired by this, variable directivity loudspeakers are applied to an ANC system. A simulation is conducted to investigate the performance of the ANC system with variable directivity loudspeaker

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13

Zhao, Guo Zhu, and Li Xuan Ma. "Research on the High-Power Directional Acoustic Transducer." Advanced Materials Research 912-914 (April 2014): 753–56. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.753.

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Through studying how to affect acoustic directivity with MATLAB software, it show that selection of a relatively larger surface of the transducer and a relatively closer transducer interval will be more preferable for directivity. While an array which possess more array element number and whose frequency of the drive signal can be as large as possible in a range, directivity will be more preferable. On the other hand, when the structure of the sound radiating surface of the transducer or array layout is symmetrical, the corresponding directivity pattern will be symmetrical. At a frequency of 1

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14

Bellows, Samuel D., and Timothy W. Leishman. "Modeling musician diffraction for artificially excited clarinet directivity measurements." Journal of the Acoustical Society of America 151, no. 4 (2022): A157. http://dx.doi.org/10.1121/10.0010960.

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Directivity measurements of musical instruments have many applications in musical, audio, and architectural acoustics. Typical measurement methods include artificially excited instruments and instruments played by live musicians. While recent advances in directivity measurement techniques enable higher resolutions for played instruments, the results are still limited in bandwidth and repeatability compared with directivity results from artificially excited instruments. However, artificially excited instruments typically neglect musician diffraction and absorption. This work compares possible a

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15

Mathews, Logan T., Hunter J. Pratt, Mark C. Anderson, and Kent L. Gee. "Directivity and sound power of rockets: A comparative analysis of source characteristics and their implementation into a predictive model." Journal of the Acoustical Society of America 154, no. 4_supplement (2023): A347. http://dx.doi.org/10.1121/10.0023752.

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Fundamental jet and rocket noise modeling includes quantifying the acoustic power and directivity characteristics of the source. While many attempts have been made to define a model for the sound power and directivity of jets and rockets, many of these models have been based on flawed measurements or methodologies. This paper presents the directivity and sound power characteristics as obtained from launched rockets. The results are compared with those in the literature. The directivity and sound power properties are used in a standard source model for rocket noise, and the resulting prediction

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16

Spudich, Paul, Badie Rowshandel, Shrey K. Shahi, Jack W. Baker, and Brian S. J. Chiou. "Comparison of NGA-West2 Directivity Models." Earthquake Spectra 30, no. 3 (2014): 1199–221. http://dx.doi.org/10.1193/080313eqs222m.

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Five directivity models have been developed based on data from the NGA-West2 database and based on numerical simulations of large strike-slip and reverse-slip earthquakes. All models avoid the use of normalized rupture dimension, enabling them to scale up to the largest earthquakes in a physically reasonable way. Four of the five models are explicitly “narrow-band” (in which the effect of directivity is maximum at a specific period that is a function of earthquake magnitude). Several strategies for determining the zero-level for directivity have been developed. We show comparisons of maps of t

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17

Pavill, Hanna, and Micah Shepherd. "The sound radiation and directivity of glockenspiel bars." Journal of the Acoustical Society of America 155, no. 3_Supplement (2024): A254. http://dx.doi.org/10.1121/10.0027407.

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The directivity of a musical instrument describes the predominant directions that sound radiates from that instrument when it is being played. The shape of an instrument, as well as the note and playing style, can greatly affect its sound radiation and directivity. The glockenspiel is a percussion instrument made of pitched metal bars of uniform thickness laid out in a keyboard pattern and set on a frame. It produces sound when the player strikes the bars with a mallet. Uniform beam theory is often used to describe the modal behavior of the individual glockenspiel bars. However, when a single

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18

Zhou, R., and L. Shafai. "Directivity enhancement by layered radomes." Canadian Journal of Physics 73, no. 7-8 (1995): 444–51. http://dx.doi.org/10.1139/p95-064.

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Single and layered radomes are often used to protect radiating elements. A two-dimensional analysis is used to investigate their influence on the antenna directivity and radiation patterns. Image-theory and integral-equation methods are used to formulate the problem for a line source and layered dielectrics of finite length over a ground plane, and solved numerically using the moment method. It is shown that, for a sufficiently long single-layer slab, the directivity enhancement is approximately equal to the square root of its relative permittivity. Properly truncating the slab can even improv

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19

Pörschmann, Christoph, and Johannes M. Arend. "Effects of hand postures on voice directivity." JASA Express Letters 2, no. 3 (2022): 035203. http://dx.doi.org/10.1121/10.0009748.

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While speaking, hand postures, such as holding a hand in front of the mouth or cupping the hands around the mouth, influence human voice directivity. This study presents and analyzes spherical voice directivity datasets of an articulated [a] with and without hand postures. The datasets were determined from measurements with 13 subjects in a surrounding spherical microphone array with 32 microphones and then upsampled to a higher spatial resolution. The results show that hand postures strongly impact voice directivity and affect the directivity index by up to 6 dB, which is more than variances

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20

Liu, Qingxi, Wenhua Song, Ye Tian, Zeying Zhang, and Guang Yuan. "On the Reproducibility and Directionality of Underwater Laser-induced Acoustic Signal." Journal of Physics: Conference Series 2486, no. 1 (2023): 012064. http://dx.doi.org/10.1088/1742-6596/2486/1/012064.

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Abstract An intense laser pulse focused in water could induce plasma expansion, which can be used as an impulsive sound source. The optoacoustic underwater source is very useful in marine applications; however, the poor reproductivity and the sharp directivity of the emitted signals is a big problem. The reproductivity and directivity of the acoustic emission by laser breakdown are measured in the laboratory experiment in this paper, and the results show that the reproductivity and directivity are both direction-dependent. The measurement also shows the feasibility of improving the reproductiv

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21

Pezzoli, Mirco, Antonio Canclini, Fabio Antonacci, and Augusto Sarti. "A comparative analysis of the directional sound radiation of historical violins." Journal of the Acoustical Society of America 152, no. 1 (2022): 354–67. http://dx.doi.org/10.1121/10.0012577.

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The directivity pattern of a musical instrument describes the sound energy radiation as a function of frequency and direction of emission. Violins exhibit a rather complex directivity pattern, which is known to show rapid variations across frequencies, and whose behavior cannot be easily predicted except in the lowest frequency range. The acoustic behavior of the violin is a fascinating research topic that has prompted numerous published works, but a thorough, comprehensive, and comparative analysis of violin directivity patterns is long overdue. In this article, we propose a set of metrics fo

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22

Xie, Junju. "Strong‐Motion Directionality and Evidence of Rupture Directivity Effects during the Chi‐Chi Mw 7.6 Earthquake." Bulletin of the Seismological Society of America 109, no. 6 (2019): 2367–83. http://dx.doi.org/10.1785/0120190087.

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Abstract This article investigates the spatial distribution, predominant direction, and variations in the intensity measures (IMs) with orientation for classified pulse‐like and nonpulse motions during Chi‐Chi Mw 7.6 earthquake. The results show evidence of high polarization for long‐period spectral accelerations at relatively large source‐to‐site distances (50–100 km) north of the Chelungpu fault. The polarization of long‐period motions shows a clear correlation with the directivity parameters’ isochrone directivity predictor and ξ, indicating a connection between directionality and rupture d

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23

Brandner, Manuel, Matthias Frank, and Alois Sontacchi. "Horizontal and Vertical Voice Directivity Characteristics of Sung Vowels in Classical Singing." Acoustics 4, no. 4 (2022): 849–66. http://dx.doi.org/10.3390/acoustics4040051.

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Singing voice directivity for five sustained German vowels /a:/, /e:/, /i:/, /o:/, /u:/ over a wide pitch range was investigated using a multichannel microphone array with high spatial resolution along the horizontal and vertical axes. A newly created dataset allows to examine voice directivity in classical singing with high resolution in angle and frequency. Three voice production modes (phonation modes) modal, breathy, and pressed that could affect the used mouth opening and voice directivity were investigated. We present detailed results for singing voice directivity and introduce metrics t

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24

Bradley, Brendon A., and Graeme Weatherill. "Consideration of near-fault effects in New Zealand seismic hazard analysis and design spectra." Bulletin of the New Zealand Society for Earthquake Engineering 58, no. 2 (2025): 108–17. https://doi.org/10.5459/bnzsee.1743.

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This paper examines the manner in which near-fault ground-motion phenomena are considered in the probabilistic seismic hazard analysis underpinning the 2022 New Zealand National Seismic Hazard Model (NZ NSHM), and its subsequent codification in the draft Technical Specification TS1170.5:2004. Directivity is already implicitly considered in the 2022 NSHM, and thus the ‘baseline’ draft TS1170.5 spectra, before any additional near-fault factor is applied. Specific studies in NZ and California suggest that explicit modelling of directivity could result in increases of up to 15-20% for 2475-year re

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25

KOYAMA, Junji. "Short Period Seismic Directivity." Zisin (Journal of the Seismological Society of Japan. 2nd ser.) 40, no. 3 (1987): 397–404. http://dx.doi.org/10.4294/zisin1948.40.3_397.

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26

Oyaba, Takashi. "Speaker system having directivity." Journal of the Acoustical Society of America 93, no. 3 (1993): 1680. http://dx.doi.org/10.1121/1.406748.

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27

Oyaba, Takashi. "Speaker system having directivity." Journal of the Acoustical Society of America 91, no. 2 (1992): 1200. http://dx.doi.org/10.1121/1.402556.

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28

Harrell, Jefferson A., and Elmer L. Hixson. "Constant directivity loudspeaker arrays." Journal of the Acoustical Society of America 91, no. 4 (1992): 2326. http://dx.doi.org/10.1121/1.403523.

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29

Williams, J. Michael, Michael D. Cerna, and Elmer L. Hixson. "Constant directivity receiving arrays." Journal of the Acoustical Society of America 91, no. 4 (1992): 2325. http://dx.doi.org/10.1121/1.403546.

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30

Chu, Wing T., Alf Warnock, and Jean‐Charles Guy. "Directivity of human talkers." Journal of the Acoustical Society of America 110, no. 5 (2001): 2664. http://dx.doi.org/10.1121/1.4777091.

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31

Leishman, Timothy W., and Samuel D. Bellows. "Musical instrument directivity measurements." Journal of the Acoustical Society of America 146, no. 4 (2019): 2822. http://dx.doi.org/10.1121/1.5136777.

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32

Pozar, D. "Directivity of omnidirectional antennas." IEEE Antennas and Propagation Magazine 35, no. 5 (1993): 50–51. http://dx.doi.org/10.1109/74.242180.

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33

Schejbal, V., J. D. Mahoney, and N. McDonald. "Directivity of planar antennas." IEEE Antennas and Propagation Magazine 41, no. 2 (1999): 60–65. http://dx.doi.org/10.1109/74.769693.

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34

Bulgakovа, A. A., N. N. Gorobets, V. A. Katrich, and V. A. Lyashchenko. "DIRECTIVITY OF ANTENNA ARRAYS." Radio physics and radio astronomy 21, no. 4 (2016): 285–97. http://dx.doi.org/10.15407/rpra21.04.285.

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35

Bodley, Martin Reed. "High directivity microphone array." Journal of the Acoustical Society of America 113, no. 6 (2003): 2957. http://dx.doi.org/10.1121/1.1588802.

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36

Bodley, Martin Reed. "High directivity microphone array." Journal of the Acoustical Society of America 116, no. 6 (2004): 3246. http://dx.doi.org/10.1121/1.1852937.

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37

Bodley, Martin Reed. "High directivity microphone array." Journal of the Acoustical Society of America 120, no. 1 (2006): 18. http://dx.doi.org/10.1121/1.2227659.

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38

Murphy, David John. "Constant directivity acoustic horn." Journal of the Acoustical Society of America 121, no. 1 (2007): 14. http://dx.doi.org/10.1121/1.2434265.

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39

Hansen, R. C. "Directivity of ring arrays." Microwave and Optical Technology Letters 18, no. 6 (1998): 370–75. http://dx.doi.org/10.1002/(sici)1098-2760(19980820)18:6<370::aid-mop2>3.0.co;2-a.

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40

Pinchera, Daniele. "On the Trade-Off between the Main Parameters of Planar Antenna Arrays." Electronics 9, no. 5 (2020): 739. http://dx.doi.org/10.3390/electronics9050739.

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The aim of this paper is two-fold. First, the trade-off between directivity, beam-width, side-lobe-level, number of radiating elements, and scanning range of planar antenna arrays is reviewed, and some simple ready-to-use formulas for the preliminary dimensioning of equispaced planar arrays are provided. Furthermore, the synthesis of sparse planar arrays, and the issue of their reduction in directivity, is analyzed. Second, a simple, yet effective, novel approach to overcome the directivity issue is proposed. The presented method is validated by several synthesized layouts; the examples show t

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41

Xu, Long Jun, and Sheng Chao Yang. "Near-Fault Directivity Spectrum for Nuclear Structure Design on Rock Site." Advanced Materials Research 243-249 (May 2011): 3820–23. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3820.

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This study is aimed at evaluating the safety implications of near-fault directivity effect on nuclear structure and facilities designed according to the Chinese code. To this end, a set of near-fault ground motions at rock site with typical forward-directivity effect is examined with emphasis on several key parameters and response spectra. The bi-normalized response spectra in terms of different corner periods are utilized to derive nuclear design spectra. It was concluded that nuclear design spectra on rock site derived from typical directivity records are significantly influenced by both mag

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42

Seo, Min-Seong, Won-Young Kim, and YoungHee Kim. "Rupture Directivity of the 2021 ML 2.2 Gwangyang, Korea, Microearthquake: Toward Resolving High-Resolution Rupture Process of a Small Earthquake." Seismic Record 2, no. 4 (2022): 227–36. http://dx.doi.org/10.1785/0320220030.

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Abstract Moderate-to-large earthquakes (M&gt;6) frequently show clear rupture directivity. Recent studies revealed that a substantial percentage of small-sized earthquakes (M&lt;∼5) display rupture directivity as well, owing to enhanced seismic monitoring. Is rupture directivity a common feature for earthquakes of all sizes? In this study, we investigated the rupture directivity of the 27 August 2021 ML 2.2 Gwangyang microearthquake that occurred at the southern tip of the Korean Peninsula by utilizing data from a recently expanded dense seismic network. The mainshock had two foreshock

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Zhong, Jiaxin, Haishan Zou, Jing Lu, and Dong Zhang. "A modified convolution model for calculating the far field directivity of a parametric array loudspeaker." Journal of the Acoustical Society of America 153, no. 3 (2023): 1439–51. http://dx.doi.org/10.1121/10.0017361.

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The far field directivity is a straightforward indicator to describe the radiation pattern of the audio sound generated by a parametric array loudspeaker (pal), but its accurate and computationally efficient prediction is still challenging at present. This paper derives two-dimensional (2D), three-dimensional (3D), and 3D axisymmetric convolution models for calculating the far field directivity based on the quasilinear solution of Westervelt equation. The obtained expressions are expressed as linear and spherical convolutions of the ultrasound directivity and Westervelt directivity for 2D and

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44

Shrestha, Sujan, Hijab Zahra, Muhammad Ali Babar Abbasi, Mohsen Asadnia, and Syed Muzahir Abbas. "Increasing the Directivity of Resonant Cavity Antennas with Nearfield Transformation Meta-Structure Realized with Stereolithograpy." Electronics 10, no. 3 (2021): 333. http://dx.doi.org/10.3390/electronics10030333.

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A simple, nearfield transformation meta-structure is proposed to increase the directivity of resonant cavity antennas (RCA). The meta-structure is comprised of 14 × 14 meta-atoms or so called “unit-cells”, adding localized phase delays in the aperture of the RCA and thus increasing its broadside directivity. A prototype of the meta-structure is additively manufactured using the stereolithograpy process and has a profile of 0.56λ. With the meta-structure integrated with the RCA, it demonstrates a measured broadside directivity of 20.15 dBi without affecting its half-power directivity bandwidth.

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45

Zhao, Liuxian, Lihua Tang, Yuxin Liu, Zhaoyong Sun, Qimin Liu, and Chuanxing Bi. "Passive directivity detection of acoustic sources based on acoustic Luneburg lens." Journal of the Acoustical Society of America 154, no. 2 (2023): 594–601. http://dx.doi.org/10.1121/10.0020541.

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This article reports an acoustic Luneburg lens (ALL) design with graded refractive index for passive directivity detection of acoustic sources. The refractive index profile of the lens is realized based on square pillars with graded variation of their dimensions. Numerical and experimental studies are conducted to investigate the performance of directivity detection. The results demonstrate that the lens designed and developed in this study is capable of precisely detecting the directivity of one acoustic source. Furthermore, the directivities of two acoustic sources can also be detected with

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46

Song, Zhongchang, Chuang Zhang, Weijie Fu, et al. "Investigation on whistle directivity in the Indo-Pacific humpback dolphin (Sousa chinensis) through numerical modeling." Journal of the Acoustical Society of America 151, no. 6 (2022): 3573–79. http://dx.doi.org/10.1121/10.0011513.

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Odontocetes have evolved special acoustic structures in the forehead to modulate echolocation and communication signals into directional beams to facilitate feeding and social behaviors. Whistle directivity was addressed for the Indo-Pacific humpback dolphin ( Sousa chinensis) by developing numerical models in the current paper. Directivity was first examined at the fundamental frequency 5 kHz, and simulations were then extended to the harmonics of 10, 15, 20, 25, and 30 kHz. At 5 kHz, the –3 dB beam widths in the vertical and horizontal planes were 149.3° and 119.4°, corresponding to the dire

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47

Sonasang, Somchat, and Niwat Angkawisittpan. "Design of Microstrip Parallel-Coupled Lines with High Directivity using Symmetric-Centered Inductors." Applied Computational Electromagnetics Society 36, no. 6 (2021): 657–63. http://dx.doi.org/10.47037/2020.aces.j.360606.

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A technique for directivity improvement of the microstrip parallel-coupled lines using symmetric-centered inductors is presented in this paper. The design procedure of the symmetric-centered inductors using the closed-form equations is given. The proposed technique was performed with a design at the operating frequency of 0.9 GHz on an FR4 substrate. Validity of the proposed technique is verified by simulations and measurements in comparisons with conventional parallel-coupled lines. The measured results exhibit the isolation of -30.10 dB and directivity of 19.28 dB at the operating frequency

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48

Zhang, Wen, Hui Zhang, Shijiu Jin, and Zhoumo Zeng. "A Two-Dimensional CMUT Linear Array for Underwater Applications: Directivity Analysis and Design Optimization." Journal of Sensors 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/5298197.

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Capacitive micromachined ultrasonic transducers (CMUTs) are one of the promising MEMS devices. This paper proposed an integrated vibration membrane structure to design a two-dimensional CMUT linear array for underwater applications. The operation frequencies for different medium have been calculated and simulated, which are 2.5 MHz in air and 0.7 MHz in water. The directivity analyses for the CMUT cell, subarray, and linear array have been provided. According to the product theorems, the directivity function of the complex array is obtained using a combination of the directivity functions of c

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Pörschmann, Christoph, and Johannes M. Arend. "Investigating phoneme-dependencies of spherical voice directivity patterns II: Various groups of phonemes." Journal of the Acoustical Society of America 153, no. 1 (2023): 179–90. http://dx.doi.org/10.1121/10.0016821.

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Abstract:

The substantial variation between articulated phonemes is a fundamental feature of human voice production. However, while the spectral and temporal aspects of the phonemes have been extensively studied, few have investigated the spatial aspects and analyzed phoneme-dependent differences in voice directivity. This paper extends our previous research focusing on the directivity patterns of selected vowels and fricatives [Pörschmann and Arend, J. Acoust. Soc. Am. 149(6), 4553–4564 (2021)] and examines different groups of phonemes, such as plosives, nasals, voiced alveolars, and additional fricati

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Makino, Yusuke, and Yasushi Takano. "Sound source directivity considering source movement." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 4 (2023): 3579–89. http://dx.doi.org/10.3397/in_2022_0505.

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Abstract:

When the source moves, frequency modulation (Doppler effect) occurs in the radiated sound, and the directivity of source changes. In addition, the source can be not located in a direction from the direction of arrival of radiated sound. Therefore, the sound pressure directivity may differ depending on whether the source is static or moving. There are two types of wave equations, one that describes sound pressure as a variable and one that describes velocity potential as a variable. When the sound source moves at a constant velocity and the equation is solved assuming that the source strength i

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