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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modeling the performance of MEMS based directional microphones

Chatzopoulos, Dimitrios. January 2008 (has links) (PDF)
Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2008. / Thesis Advisor(s): Kapolka, Daphne ; Karunasiri, Gamani. "December 2008." Description based on title screen as viewed on January 30, 2009. Includes bibliographical references (p. 97-98). Also available in print.
2

Characterization of MEMS a directional microphone with solid and perforated wings

Muamad, Norbahrin. January 2009 (has links) (PDF)
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2009. / Thesis Advisor(s): Karunasiri, Gamani ; Denardo, Bruce. "June 2009." Description based on title screen as viewed on July 14, 2009. DTIC Identifiers: Directional microphone, soimumps, ormia ochracea, biomimetic, fly hearing. Author(s) subject terms: SOIMUMPs, MEMS, Ormia Ochracea, Biomimetic, Directional Microphone, Sensor, Microphone, Fly Hearing, Undersea Warfare. Includes bibliographical references (p. 39). Also available in print.
3

An investigation of microphonic action in porous media

Burr, Horace Kelsey, January 1937 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1937. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 12).
4

Structure analysis and characterization of a biomimetic silicon microphone

Gao, Jia. January 2005 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Mechanical Engineering Dept., 2005. / Includes bibliographical references.
5

Development of a weatherproof windscreen for a microphone array /

Hill, Jeffrey R., January 2005 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 69-70).
6

Micromachined in-plane acoustic pressure gradient sensors

Kuntzman, Michael Louis 08 September 2015 (has links)
This work presents the fabrication, modeling, and characterization of two first-generation acoustic in-plane pressure gradient sensors. The first is a micromachined piezoelectric microphone. The microphone structure consists of a semi-rigid beam structure that rotates about torsional pivots in response to in-plane pressure gradients across the length of the beam. The rotation of the beam structure is transduced by piezoelectric cantilevers, which deflect when the beam structure rotates. Sensors with both 10 and 20-μm-thick beam structures are presented. An analytical model and multi-mode, multi-port network model utilizing finite-element analysis for parameter extraction are presented and compared to acoustic sensitivity measurements. Directivity measurements are interpreted in terms of the multi-mode model. A noise model for the sensor and readout electronics is presented and compared to measurements. The second sensor is a capacitive sensor which is comprised of two vacuum-sealed, pistons coupled to each other by a pivoting beam. The use of a pivoting beam can, in principle, enable high rotational compliance to in-plane small-signal acoustic pressure gradients, while resisting piston collapse against large background atmospheric pressure. A design path towards vacuum-sealed, surface micromachined broadband microphones is a motivation to explore the sensor concept. Fabrication of surface micromachined prototypes is presented, followed by finite element modeling and experimental confirmation of successful vacuum-sealing. Dynamic frequency response measurements are obtained using broadband electrostatic actuation and confirm a first fundamental rocking mode near 250 kHz. Successful reception of airborne ultrasound in air at 130 kHz is also demonstrated, and followed by a discussion of design paths toward improve signal-to-noise ratio beyond that of the initial prototypes presented. A method of localizing sound sources is demonstrated using the piezoelectric sensor. The localization method utilizes the multiple-port nature of the sensor to simultaneously extract the pressure gradient and pressure magnitude components of the incoming acoustic signal. An algorithm for calculating the sound source location from the pressure gradient and pressure magnitude measurement is developed. The method is verified by acoustic measurements performed at 2 kHz. / text
7

Near-field microphone array design for a hands-free system in a vehicle by using the nash genetic algorithm

Paik, Soonkwon 28 August 2008 (has links)
Not available / text
8

Toward a microphone technique for Dolby Surround encoding

Cook, Peter January 1991 (has links)
Dolby Surround technology offers consumers surround sound in their home via a 4:2:4 encode/decode matrix. Although originally intended for audio accompanying visual media, the system has potential as a music-only playback system. / The purpose of the thesis is to investigate this potential, particularly as it applies to acoustic music recording. Dolby Surround encode and decode technology and its relevance to acoustic music reproduction is reviewed. The classic stereo microphone techniques are discussed with particular attention paid to each one's theoretical ability to "encode" information for the Dolby Surround decoder. Practical limitations and benefits of these well-known methods are considered. / Recently proposed microphone techniques are reviewed in theory and in practice and are found to provide many solutions. Methods for optimizing the decoder technology for music reproduction are suggested. The paper is relevant to any acoustic recording application for a number of surround systems as well as for conventional stereo and mono.
9

On the theory of second-order soundfield microphone

Cotterell, Philip S. January 2002 (has links)
No description available.
10

Design and fabrication of an air-bridge microphone /

Jeran, Paul L. January 1992 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references (leaves 54-55).

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