Aircraft sound environment reproduction: Sound field reproduction inside a cabin mock-up using microphone and actuator arrays
Philippe-Aubert Gauthier, Cedric Camier, Olivier Gauthier, Yann Pasco, and Alain Berry
Sound environment reproduction of various flight conditions in aircraft cabin mock-ups is useful for the design, demonstration and jury testing of interior aircraft sound quality. To provide a faithfully perceived sound environment, time, frequency and spatial characteristics should be preserved. Ph ... [POMA 19, 055008 (2013)] published Fri May 17, 2013.
Quantification of the thorax-to-abdomen breathing ratio for breathing motion modeling
Benjamin M. White, Tianyu Zhao, James Lamb, Jeffrey D. Bradley, and Daniel A. Low
Constructal paddle design with fingers
E. Cetkin, S. Lorente, and A. Bejan
Here, we show how the performance of a paddle that pushes a fluid can be increased by making parallel slits through it. The slit spacing is varied to see its effect on the drag force and the maximum stress in the paddle. The effect of water speed and paddle dimensions is documented. Designs with one ... [J. Appl. Phys. 113, 194902 (2013)] published Thu May 16, 2013.
Ultrasonic transducers with directional converters of vibration of longitudinal-longitudinal (L-L) type and longitudinal-longitudinal-longitudinal (L-L-L) type intended to work in gaseous media
Tadeusz Gudra, Lukasz P. Palasz, and Krzysztof J. Opielinski
The study presents a realised concept of an ultrasonic transducer intended to work in a gaseous medium, that radiates a focused ultrasonic beam in many directions simultaneously. The use of a L-L type vibration direction converter makes it possible to radiate ultrasonic energy in a required directio ... [POMA 19, 065083 (2013)] published Tue May 14, 2013.
A low density, high stiffness flat loudspeaker with improved sound frequency response
Jen-Hsuan Ho and Arthur Berkhoff
This paper presents a novel flat loudspeaker with improved sound frequency response. Flat loudspeakers provide advantages of compact dimensions and high durability. Known flat loudspeaker technology is based on high modal density. However, the resonances in the panel are complex and difficult to co ... [POMA 19, 065082 (2013)] published Tue May 14, 2013.
Evaluation of system configuration to check the suitability for the sound field rendering using the inverse approach
Jeong-Guon Ih, Wan-Ho Cho, and Seung-Wan Hong
Sound field control by the inverse approach based on the acoustical holography is useful to render an arbitrary target sound field within a selected control zone if the target condition is given in a detailed format. This method needs information on the various factors constituting the total system: ... [POMA 19, 055005 (2013)] published Tue May 14, 2013.
Fluctuation strength on real sound: motorbike exhaust and marimba tremolo
Masanobu Miura and Nozomiko Yasui
Psychoacoustics research has been contributed on evaluating the timbre of acoustic signals. The Fluctuation Strength (FS) has been respected as the important index which describes the sensory fluctuation of the acoustic signal based on its amplitude, frequency and the combination of them as well. Al ... [POMA 19, 050194 (2013)] published Tue May 14, 2013.
Quantitative assessment of spatial sound distortion by the semi-ideal recording point of a hear-through device
Pablo Hoffmann, Flemming Christensen, and Dorte Hammershoi
A hear-through device combines a microphone and earphone in an earpiece so that when worn, one per ear, it can work as an acoustically transparent system allowing for simultaneous individual binaural recording and playback of the real sound field at the ears. Recognizing the blocked entrance to the ... [POMA 19, 050018 (2013)] published Tue May 14, 2013.
Extension of perceived source width using sound field reproduction systems
Jung-Woo Choi
We propose a method to extend the perceived spatial width of a virtual sound source using an array of loudspeakers. In general, the control of perceived source width or apparent source width (ASW) has been attempted by decreasing the inter-aural correlation, i.e., the correlation between two signals ... [POMA 19, 055006 (2013)] published Tue May 14, 2013.
Virtual sound source generation: Its various methods and performances
Dong-Soo Kang, Jung-Min Lee, Jung-Woo Choi, Minho Song, and Yang-Hann Kim
There are many means to generate a virtual sound source, or sources in the region of interest. For example, WFS (Wave Field Synthesis) or HOA (Higher Order Ambisonics) are good examples. These methods normally assume that loudspeakers are spatially distributed in the space. The region of interest wh ... [POMA 19, 055004 (2013)] published Tue May 14, 2013.
Planned versus achieved acoustical performance and occupant satisfaction for an office fit-out
Ryan Bessey
The purpose of the project was to move 500 office workers separated between two aging buildings into one new larger building. The goal was to provide a building with improved acoustics related to background sound level, speech privacy, and speech intelligibility. As the project's acoustic consultan ... [POMA 19, 040129 (2013)] published Tue May 14, 2013.
The teachers perspective on noise in the classroom
Ana Jaramillo, Michael Ermann, and Patrick Miller
A survey was sent to 3rd grade teachers in Orange County, FL to find out about their noise awareness and coping strategies. Results of the survey were also correlated to mechanical system type and achievement data. Preliminary analyses show very little awareness on mechanical noise by teachers but a ... [POMA 19, 040126 (2013)] published Tue May 14, 2013.
Effects of background noise alternating between two levels at varying time intervals on human perception and performance
Andrew Hathaway and Lily M. Wang
This research experiment aims to better quantify human perception and performance under increased background noise levels of varying intervals. Twenty-seven participants were tested over five 30 minute sessions where they were subjected to RC-29(H) and RC-47(RV) conditions created by broadband nois ... [POMA 19, 040121 (2013)] published Tue May 14, 2013.
Acoustical characteristics of Technology Educational Shops in British Columbia
Ahmed Summan and Murray Hodgson
Technology Educational Shops (TES) are designed to develop high school students' technological literacy. Their acoustical conditions play a dominant role in the quality of these environments. TES are, at the same time, classrooms for learning and industrial workshops for making things. Each use has ... [POMA 19, 040112 (2013)] published Tue May 14, 2013.
Evaluation of noise climate in a campus environment using geospatial technology
Rajasekar Elangovan, Pari Yadava Mudaliar, Khaleelur Rahaman, Ravi Muttavarapu, and Venkateswaran Rajan
This study focuses on experimental evaluation of outdoor noise climate in an office campus which is spread across 27 acres and investigation of its impact on the adjoining office buildings. For this purpose, a base map of the campus was prepared from the recent high spatial resolution satellite ima ... [POMA 19, 040057 (2013)] published Tue May 14, 2013.
The Diverse Environments Multi-channel Acoustic Noise Database (DEMAND): A database of multichannel environmental noise recordings
Joachim Thiemann, Nobutaka Ito, and Emmanuel Vincent
Multi-microphone arrays allow for the use of spatial filtering techniques that can greatly improve noise reduction and source separation. However, for speech and audio data, work on noise reduction or separation has focused primarily on one- or two-channel systems. Because of this, databases of mult ... [POMA 19, 035081 (2013)] published Tue May 14, 2013.
Refining the stereo technique for augmented ambience gradient: Improvements in stereo image, spatial envelopment, and mixing flexibility
David J. Tagg and Kevin Fallis
While working on location, recording engineers are often challenged by insufficient monitoring capabilities. Poor (temporary control room) acoustics and/or mandatory headphone monitoring can make judgments regarding microphone choice and placement difficult. This compromised monitoring often leads t ... [POMA 19, 035039 (2013)] published Tue May 14, 2013.
Acoustic analysis of turbine generator to predict overall noise using statistical energy analysis methodology
Vasudev S. Nilajkar, Sadeo Ramtahal, and Anil Tolpadi
In the growing regions across the globe, products are being differentiated not only by their performance but also on characteristics like noise, aesthetics, ergonomics, etc. Noise norms are getting more and more stringent and customers are looking for quieter products. Engineers and technicians now ... [POMA 19, 030125 (2013)] published Tue May 14, 2013.
Mitigation of excessive acoustic compliance and trapped volume insertion gain in ear-sealing listening devices
Stephen D. Ambrose, Samuel P. Gido, and Todd Ricketts
When a sound producing device is sealed in the ear canal, acoustical compliances resulting from pressurization of the trapped volume lead to dramatic boosts in SPL, up to 60 dB, especially at low frequencies. This has been found to result in listener fatigue, and to trigger the acoustic (stapedius) ... [POMA 19, 030094 (2013)] published Tue May 14, 2013.
Design, development and testing of transducers for creating spiral waves for underwater navigation
David Brown, Corey Bachand, and Boris Aronov
Design, development and testing of transducers for creating spiral waves for underwater navigation The use of spiral waves for underwater acoustic navigation has received much attention in recent years. A spiral wave is characterized as a diverging wavefront that is omnidirectional by magnitude but ... [POMA 19, 030089 (2013)] published Tue May 14, 2013.
Improving the focal quality of the time reversal acoustic noncontact source using a deconvolution operation
Brian E. Anderson, T. J. Ulrich, and Pierre-Yves Le Bas
The time reversal acoustic noncontact source (TRANS) utilizes time reversal (TR) from several transducers arranged in a cavity to focus energy onto a solid surface to allow inspection of that surface. The advantage of TRANS is that multiple transducers may be used to increase the amplitude of the fo ... [POMA 19, 030080 (2013)] published Tue May 14, 2013.
Design of resonant frequencies for piezoelectric actuator with integrated components
Jun Kuroda, Yasuharu Onishi, Motoyoshi Komoda, Yasuhiro Oikawa, and Yoshio Yamasaki
Piezoelectric actuators are used in a wide range of electrical devices, including piezoelectric speakers, buzzers, haptics and ultrasonic transducers. For piezoelectric actuator systems used in mobile devices, the most important issue is improving the electromechanical conversion efficiency. The pow ... [POMA 19, 030066 (2013)] published Tue May 14, 2013.
Investigation of vibrations of piezoelectric spherical shells with axisymmetric holes
David Brown and Colton T. Brown
An experimental investigation of the vibration of radially polarized thin-walled piezoelectric ceramic spherical shells with axisymmetric holes is presented. Piezoelectric spherical electroacoustic transducers having holes at their poles to permit passage of wires, cables, or structural members is o ... [POMA 19, 030065 (2013)] published Tue May 14, 2013.
Cantilever mode piston transducer array
John Butler and Alexander L. Butler
The underwater sound cantilever mode transducer uses a piston, tail mass, dual piezoelectric cantilever benders and mechanical arms for translating lateral bending cantilever motion to piston motion in a direction normal to the caltilever motion. This compact design provides a wide band response and ... [POMA 19, 030044 (2013)] published Tue May 14, 2013.
The Efficiency of Receivers Used in Hearing Aid Devices
Michael Salameh
Current drain is one of the most important considerations in the hearing aid design. It is determined mainly by the receiver impedance. Recently, many additional features and technologies such as wireless are used in the hearing aid devices. These capabilities increase the current drain further. Eff ... [POMA 19, 030043 (2013)] published Tue May 14, 2013.
New planar nano-gauge detection microphone: analytical and numerical acoustic modeling
Cecile Guianvarc'h, Thierry Verdot, Jaroslaw Czarny, Emmanuel Redon, Kerem Ege et al.
The miniaturization of microphones is of great interest for several fields, such as medical applications (audio implants), or consumer electronics (cell phones). Almost all existing miniature microphones rely on electrostatic transduction and offer good performances (sensitivity, frequency bandwidth ... [POMA 19, 030040 (2013)] published Tue May 14, 2013.
Examination of acoustic mechanism for compact acoustic reproduction systems
Kosuke Sugihara and Yoshinobu Kajikawa
In this paper, we propose a method for analyzing compact acoustic reproduction systems (e.g. mobile phones) through acoustic equivalent circuits. Measured responses of compact acoustic reproduction systems cannot be represented accurately by the analysis based on the conventional acoustic theory. Ac ... [POMA 19, 030038 (2013)] published Tue May 14, 2013.
A new loudspeaker for low frequency radiation by linear motion type piezoelectric ultrasonic actuators
Hiroya Saito, Hirokazu NEGISHI, Juro OHGA, Ikuo OOHIRA, Kunio OISHI et al.
The authors had proposed new direct-radiator loudspeaker constructions with a conventional paper cone radiator driven by Ultrasonic Motors (=USM), as a substitution for voice-coil motor. However, those models needed a revolution to linear motion conversion mechanism, and avoiding zero region non lin ... [POMA 19, 030026 (2013)] published Tue May 14, 2013.
Loudspeaker for low frequency signal driven by four piezoelectric ultrasonic motors
Juro Ohga, Hirokazu Negishi, Ikuo OOHIRA, Hiroya Saito, Kunio Oishi et al.
The authors are developing a completely new direct-radiator loudspeaker as an alternative of the conventional electrodynamic loudspeaker. It is driven by continuous revolution of piezoelectric ultrasonic motors, It is useful for radiation of very low frequency signal because it shows almost flat pha ... [POMA 19, 030024 (2013)] published Tue May 14, 2013.
Electroacoustic metamaterials: achieving negative acoustic properties with shunt loudspeakers
Herve Lissek
Acoustic metamaterials constitute a new class of structures that exhibit acoustic properties not readily available in nature. These properties can be a negative mass density, expressing the opposition of the acceleration of a particle to the application of pressure, or a negative bulk modulus, signi ... [POMA 19, 030023 (2013)] published Tue May 14, 2013.
Performance of transducers with segmented piezoelectric stacks using materials with high electromechanical coupling coefficient
Stephen C. Thompson, Richard J. Meyer, and Douglas C. Markley
Underwater acoustic transducers often include a stack of thickness polarized piezoelectric material pieces of alternating polarity interspersed with electrodes and bonded together. The stack is normally much shorter than a quarter wavelength at the fundamental resonance frequency, so that the mechan ... [POMA 19, 030021 (2013)] published Tue May 14, 2013.
Acoustic characteristics of a flexible sound generator based on thermoacoustic effect
Takehiro Sugimoto and Yoshiki Nakajima
A flexible sound generator based on the thermoacoustic effect was proposed for use with thin and flexible devices. The proposed sound generator was composed of three thin films made of aluminum, polyimide, and graphite for effective interaction between acoustic energy and heat. The aluminum function ... [POMA 19, 030004 (2013)] published Tue May 14, 2013.
Heat transfer enhancement through thermoacoustically-driven streaming
Randall A. Ali and Steven L. Garrett
We recently reported on a simple standing-wave thermoacoustic engine that was intended for use as a self-powered monitor of temperature within a resonator that was similar to a nuclear fuel rod [JASA 132 (3) Pt. 2, 1993-1994 (2012)]. An additional potential benefit of such a device is the enhanced ... [POMA 19, 030001 (2013)] published Tue May 14, 2013.
New implementation of multi-microphone recording technique to simulate music ensembles in room acoustic auralizations
Alban A. Bassuet, Terence Caulkins, Joseph K. Digerness, and Glenn A. KnicKrehm
This paper describes a method to record large musical ensembles for use in computer simulations and auralization. The method uses a multi-microphone hemispherical array distributed over an orchestra playing on a hard floor. A ray tracing program models the orchestra as sectors of a hemisphere corres ... [POMA 19, 015135 (2013)] published Tue May 14, 2013.
Letters from the edge: Less conventional acoustical solutions
Jack B. Evans
The essence of acoustical analysis and problem solving still is source - path - receiver, yet, as standards, criteria and products evolve, solution precedents should be revalidated or invalidated, and new, innovative approaches should be considered. While weighing the best interests of the client, ... [POMA 19, 015091 (2013)] published Tue May 14, 2013.
Assessing the acoustics of offices: a case of standardization
Marc Asselineau and Aline Gaulupeau
Standards are supposed to help promote better understanding between the various interested parties. As such they can help an end user understand what the acoustic performances of his future premises will be... as long as such a standard exists. Over the years, various standards have been developed b ... [POMA 19, 015080 (2013)] published Tue May 14, 2013.
Physical and subjective factors of spatial envelopment impression of surround sound reproduction
Toru Kamekawa and Atsushi Marui
How we feel envelopment? For the evaluation of spatial impression, ``envelopment' is one of the key issues among several attributes of spatial impression. When the authors attempted to elicit common attributes from surround sound recordings by triadic elicitation procedure, three attributes, ``brigh ... [POMA 19, 015057 (2013)] published Tue May 14, 2013.
Electric guitar - A blank canvas for timbre and tone
Alexander U. Case, Agnieszka Roginska, Justin D. Mathew, and Jim Anderson
The electric guitar is a complex mechanical, electrical, and acoustic system, invented less than a century ago. While more traditional instruments such as voices and violins, trumpets and tympani, piano and piccolo might possess innate traits that most listeners easily identify, the electric guitar ... [POMA 19, 015039 (2013)] published Tue May 14, 2013.
Robustness analysis of room equalization for soundfield reproduction within a region
Dumidu S. Talagala, Wen Zhang, and Thushara D. Abhayapala
Recent works on soundfield reproduction have presented several methods of recreating a desired soundfield within a region. Estimation or prior knowledge of the inverse reverberant channels now becomes an essential element of equalizing the room effects. However, it has been shown that designing poin ... [POMA 19, 015023 (2013)] published Tue May 14, 2013.
Analytical solution of the problem of the rise of a Taylor bubble
Yuri B. Zudin
In the classical works of Prandtl and Taylor devoted to the analysis of the problem of the rise of a Taylor bubble in a round tube, a solution of the Laplace equation is used, which contains divergent infinite series. The present paper outlines a method for the correct analysis of the mentioned prob ... [Phys. Fluids 25, 053302 (2013)] published Mon May 13, 2013.
Would be the photon a composed particle? / Sobre a possibilidade da quantiza\c{c}\~ao dos fluxos de campo na radia\c{c}\~ao eletromagn\'etica. (arXiv:1305.3602v1 [physics.gen-ph])
ePrint arXiv http://arXiv.org/