DOCSLIB.ORG

Theory and Simulation of Streaming and Radiation Forces at Ultrasound Resonances in Microfluidic Devices

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Theory and Simulation of Streaming and Radiation Forces at Ultrasound Resonances in Microfluidic Devices Downloaded from orbit.dtu.dk on: Dec 17, 2017 Acoustofluidics: Theory and simulation of streaming and radiation forces at ultrasound resonances in microfluidic devices Bruus, Henrik Published in: Acoustical Society of America. Journal Publication date: 2009 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Bruus, H. (2009). Acoustofluidics: Theory and simulation of streaming and radiation forces at ultrasound resonances in microfluidic devices. Acoustical Society of America. Journal, 125(4), 2592-2592. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. TUESDAY MORNING, 19 MAY 2009 GRAND BALLROOM II, 8:00 A.M. TO 12:00 NOON Session 2aAAa Architectural Acoustics: Multiple Channel Systems in Room Acoustics Ning Xiang, Cochair Architecture, Rensselaer Polytechnic Inst., Troy, NY 12180 Boaz Rafaely, Cochair Electrical and Computer Engineering Dept., Ben Gurion Univ., Beer Sheva, Israel Chair’s Introduction—8:00 Invited Papers 2a TUE. AM 8:05 2aAAa1. A multi-channel audio system based on the theory of integral equations. Filippo M. Fazi and Philip A. Nelson ͑Inst. of Sound and Vib. Res., Univ. of Southampton, Highfield, S0171BJ, Southampton, U.K., [email protected]͒ The basics of a multi-channel audio system, which attempts the reproduction of a desired sound field, are presented. The system’s hardware consists of a three-dimensional array of loudspeakers, and can be used in combination with a specially designed microphone array. The mathematical fundamentals on which this technique is grounded consist of the formulation of the problems as an integral equation. The loudspeaker signals are determined from the knowledge of the target sound field on the boundary of a given control volume. The solution to this inverse problem is computed performing a singular value decomposition of the integral operator involved. For some simple array geometries it is possible to calculate an analytical solution to the problem. A regularization method is applied, as required by the ill-posed nature of the inverse problem under consideration. Some insight into the physical meaning of the ill- posedness is given and some analogies to near-field acoustic holography are suggested. The effectiveness of the method proposed has been verified experimentally and some of the experimental results are presented. Finally, it is shown how this technique has been suc- cessfully applied to the design of a multi-channel auralization system for room acoustics. 8:25 2aAAa2. Representation of the musical instruments directivity using dodecahedron loudspeakers. Gottfried Behler and Martin Pollow ͑Inst. of Tech. Acoust., RWTH Aachen Univ., 52056 Aachen, Germany, [email protected]͒ Room-acoustical measurements in general are performed with omnidirectional sound sources. With respect to auralization, such an impulse response may not be ideal since it does not represent the situation playing an instrument in the room. To achieve the directivity of a real source ͑such as an instrument or human voice͒ with a technical sound source ͑a loudspeaker͒ requires either to copy the body and the surface velocity distribution of that particular source or to reproduce the directional pattern of the radiation using a multiple source configuration like a dodecahedron loudspeaker array with independent excitation of each transducer. The advantage of the latter method is obvious since one single source is able to provide different directivities by changing the excitation profile. To maintain the appropriate excitation of each individual transducer, different approaches can be made. The method described here uses spherical har- monics decomposition of the target radiation pattern and a subsequent calculation of the frequency dependent excitation coefficients for each transducer. The advantage of this method is a flexible and fast calculation delivering filters that can be used either for real time convolution or off-line processing of the measuring signals. To measure the instruments directivity an array with 32 microphones is used. 8:45 2aAAa3. Considering modal aliasing in the implementation of an acoustic echo canceller in the wave domain. Martin Schneider and Walter Kellermann ͑Multimedia Commun.s and Signal Processing, Univ. Erlangen-Nuremberg, Cauerrstr 7, 91058 Erlangen, Ger- many, schneider,[email protected]͒ Traditional multichannel acoustic echo cancellation applied to wave field synthesis systems is computationally extremely expensive due to the large number of channels to be identified. By using wave domain adaptive filtering ͑WDAF͒ one is able to choose an ap- proximation which neglects the interaction ͑exchange of energy͒ between different modes. This reduces the number of necessary adap- tive filter coefficients drastically. Furthermore, it allows to use computationally relatively inexpensive single-channel filter adaptation algorithms. Then, however, modal aliasing due to the limited resolution of the used microphone array becomes a significant problem since it constitutes an interaction between different modes with respect to the microphone signals. The effects of modal aliasing on the adaptation behavior of a WDAF-based echo cancellation system are analyzed and a modified wave domain representation of the syn- thesized wave field is proposed which reflects the limited resolution of the microphone array. 2543 J. Acoust. Soc. Am., Vol. 125, No. 4, Pt. 2, April 2009 157th Meeting: Acoustical Society of America 2543 Downloaded 29 Jun 2010 to 192.38.67.112. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp 9:05 2aAAa4. Spherical harmonic beamforming for room acoustic analysis. Gary W. Elko and Jens Meyer ͑mh acoustics LLC, 25A Summit Ave., Summit, NJ 07901͒ We describe the potential of using a spherical beamforming microphone array to investigate the spatial correlation of sound fields in rooms. We are building spherical microphone arrays consisting of many acoustic pressure sensors mounted appropriately on the surface of a rigid sphere. Our associated spherical eigenbeamformer decomposes the sound-field into spatially orthonormal spherical harmonics up to third-order. We refer to the signals from the eigenbeamformer as eigenbeams. All eigenbeams have phase centers at the physical center of the array. Due to the orthonormal property of the eigenbeamformer, a diffuse field ideally results in zero correlation between the eigenbeams. Therefore, by measuring the cross-correlation between the eigenbeam signals, one can investigate the prox- imity to the isotropy ͑or “diffuseness”͒ of the sound-field. Simultaneously, the underlying eigen-beam patterns can be steered without effecting the orthonormality property. How the cross-correlation function changes with general orientation of the eigenbeams is another potential measure for sound field diffuseness in rooms. We will show some real room measurements demonstrating the potential use- fulness of this approach. 9:25 2aAAa5. Imaging room acoustics with the audio camera. Adam O’Donovan, Ramani Duraiswami, Nail A. Gumerov, and Dmitry N. Zotkin ͑Perceptual Interfaces and Reality Lab., Dept. of Comput. Sci. Univ. of Maryland, College Park, MD 20742͒ Using a spherical microphone array and real time signal processing using a graphical processing unit ͑GPU͒, an audio camera has been developed. This device provides images of the intensity of the sound field arriving at a point from a specified direction to the spherical array. Real-time performance is achieved via use of GPUs. The intensity can be displayed integrated over the whole frequency band of the array, or in false color, with different frequency bands mapped to different color bands. The resulting audio camera may be combined with video cameras to achieve multimodal scene capture and analysis. A theory of registration of audio camera images with video camera images is developed, and joint analysis of audio and video images performed. An interesting application of the audio camera is the imaging of concert hall acoustics. The individual reflections that constitute the impulse response measured at a particular seat may be imaged, and their spatial origin determined. Other applications of the audio camera to people tracking, noise suppression, and camera pointing are also presented. ͓Work partially supported by NVIDIA and the VA.͔ 9:45 2aAAa6. Proposed method to measure the diffusion coefficient. Peter D’Antonio ͑651-C Commerce Dr., Upper Marlboro, MD 20774, [email protected]͒ A method to measure the uniform diffusion coefficient has been published as an AES Information Document ͓AES-4id-2001, JAES, Vol. 9, pp. 148–165 ͑March 2001͔͒. The method utilizes 37 fixed pressure zone microphones separated by 5 degrees located ona1m semicircle and a loudspeaker located ona2mconcentric
Load more

Recommended publications
  • Ocean Noise Strategy Roadmap
    Ocean Noise Strategy Roadmap Ocean Noise Strategy Roadmap Jason Gedamke, Jolie Harrison, Leila Hatch, Robyn Angliss, Jay Barlow, Catherine Berchok, Chris Caldow, Manuel Castellote, Danielle Cholewiak, Monica L. DeAngelis, Robert Dziak, Ellen Garland, Shane Guan, Sean Hastings, Marla Holt, Ben Laws, David Mellinger, Sue Moore, Thomas J. Moore, Erin Oleson, Jacqueline Pearson-Meyer, Wendy Piniak, Jessica Redfern, Teri Rowles, Amy Scholik-Schlomer, Aileen Smith, Melissa Soldevilla, John Stadler, Sofie Van Parijs, Charles Wahle ii Table of Contents Executive Summary 1 Chapter 1—The NOAA Ocean Noise Strategy and Managed Species 6 Chapter 2—Can You Hear Me Here? Managing Acoustic Habitat in U.S. Waters 27 Chapter 3—Enhancing NOAA’s Ability to Characterize Aquatic Soundscapes 45 Chapter 4— NOAA Ocean Noise Strategy Implementation Case Studies 60 Case Study 1: Assessing the Risk of Chronic Noise from Commercial Ships to 63 Large Whale Acoustic Habitat Case Study 2: Managing Noise Impacts on Spawning Areas Used by 81 Acoustically Sensitive and Commercially Important Fish and Invertebrate Species Appendix A— The Status of Science for Assessing Noise Impacts on NOAA-Managed 91 Species Appendix B— Presence, Abundance, Distribution, Density, Habitat Use and 113 Population Trends Appendix C— Spreadsheet of Potential Authorities (e.g. Statutes, Executive Orders) 121 to Address Ocean Noise Issues Appendix D— NOAA Ocean Noise Strategy Cross-Office Team 138 iii List of Figures Page Figure 1-1. Potential Consequences of Disturbance conceptual model of the relationships 11 linking disturbance to changes in behavior and physiology, health, vital rates, and population dynamics. Figure 2-1. Illustration of potential acoustically-mediated information in a marine 28 community.
    [Show full text]
  • Porównanie Skuteczności Urządzeń Oxybaria S I Laserobaria S W Skojarzonym Leczeniu Fizykalnym Owrzodzeń Kończyn Dolnych
    Lekarz Mikołaj Pietrzak Porównanie skuteczności urządzeń Oxybaria S i Laserobaria S w skojarzonym leczeniu fizykalnym owrzodzeń kończyn dolnych Rozprawa na stopień doktora nauk medycznych Promotor: prof. dr hab. n. med. Grzegorz Cieślar Katedra i Oddział Kliniczny Chorób Wewnętrznych, Angiologii i Medycyny Fizykalnej Kierownik Katedry: prof. dr hab. n. med. Grzegorz Cieślar Wydział Lekarski z Oddziałem Lekarsko-Dentystycznym w Zabrzu Śląski Uniwersytet Medyczny w Katowicach Zabrze 2019 Pobrano z Repozytorium Śląskiego Uniwersytetu Medycznego w Katowicach / Downloaded from Repository of Medical University of Silesia 2021-09-26 Mikołaj Pietrzak Oddział Kliniczny Chorób Wewnętrznych, Angiologii i Medycyny Fizykalnej Szpitala Specjalistycznego nr 2 w Bytomiu 41-902 Bytom, ul. Batorego 15 e-mail: [email protected] RECENZENCI: Prof. dr hab. n. med. Andrzej Szuba Katedra i Klinika Angiologii, Nadciśnienia Tętniczego i Diabetologii Wydział Lekarski Kształcenia Podyplomowego Uniwersytet Medyczny im. Piastów Śląskich we Wrocławiu Dr hab. n. o kult. fiz. Jan Szczegielniak Prof. nadzw. PO Katedra Fizjoterapii Klinicznej Instytut Fizjoterapii Wydział Wychowania Fizycznego i Fizjoterapii Politechnika Opolska w Opolu 1 Pobrano z Repozytorium Śląskiego Uniwersytetu Medycznego w Katowicach / Downloaded from Repository of Medical University of Silesia 2021-09-26 SPIS TREŚCI WYKAZ STOSOWANYCH SKRÓTÓW…………………………………………. 4 WYKAZ TABEL……………………………………………………………………. 6 WYKAZ RYCIN…………………………………………………………………….. 8 1. WSTĘP…………………………………………………………………………. 9 1.1. Rany przewlekłe………………………………………………………….... 9 1.1.1. Definicja, epidemiologia, powikłania……………………………….. 9 1.1.2. Etiopatogeneza owrzodzeń w obrębie kończyn dolnych ………… 10 1.1.3. Proces gojenia ran przewlekłych…………………………………… 13 1.1.4. Leczenie owrzodzeń w obrębie kończyn dolnych ………………… 15 1.1.5. Rokowanie w przypadku owrzodzeń w obrębie kończyn dolnych 16 1.2. Wybrane metody fizykalne stosowane w leczeniu owrzodzeń kończyn dolnych……………………………………………………………………… 17 1.3.
    [Show full text]
  • Nonlinear Ultrasound Spectroscopy for Chemical Quantification
    Nonlinear Ultrasound Spectroscopy for Chemical Quantification Jonathan R. Dion Department of Chemistry McGill University, Montreal Quebec, Canada August 2011 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Doctor of Philosophy © Jonathan R. Dion, 2011 Abstract Analyte quantification is an area of great practical interest for biomedical and commercial applications. Measurement in highly scattering media such as tissue, blood, and other biological fluids is challenging using conventional spectroscopic methods. Likewise, measurement of compounds on-line or in opaque containers can be extremely challenging. This thesis presents general approaches for analyte quantification in liquids by the frequency analysis of ultrasound waves. Initially, this research focused on the quantification of analytes using dispersive hydrogel sensors. These sub-micron hydrogels vibrate at characteristic resonance frequencies when exposed to ultrasound. The resonance frequencies of the sensors could be modulated by generating molecularly imprinted pockets that would recognize and bind to molecules. Changes in the measured ultrasound frequency spectrum upon binding could then be detected. Using this approach, quantification of theophylline between 10 μM and 6.1 mM was shown. Improvements in analyte quantification using ultrasound were made by designing hydrogel sensors coupled to antibodies. The high affinity of antibodies for a specific antigen allowed the quantification of acetaminophen between 3.5 nM and 20.8 nM. The highly selective antibodies were also demonstrated to allow acetaminophen determination in a variety of biological media. Though the ultrasound frequency profiles change in the different media, frequencies used for multilinear determination of the analyte were ii clustered in certain regions of the spectrum.
    [Show full text]
  • Audio and Tactile Interfaces to Mobility Aids for the Blind
    Interfaces for multi-sensor systems for navigation for the blind Penny Probert, David Lee and Gordon Kao Robotics Research Group, Department of Engineering Science, University of Oxford, 19 Parks Road, Oxford, OX1 3PJ, ENGLAND Tel: +44-1865-273926 Fax: +44-1865-273908 [email protected], [email protected] ABSTRACT This paper describes work towards a multi-sensor system to assist blind people to move around an urban or indoor environment. The communication of navigation information is constrained by both the type of information imparted and, in many ways more crucially, by the type of information which real sensors can extract. In this paper we describe the use of ultrasound to provide two types of information: first the low level directional information which may be provided currently by a guide dog and then information on features to allow the blind person to locate and direct themselves within the environment. A directional system with a simple vibrator interface is described and its performance assessed by a group of users. Finally we discuss the possibility of feature extraction for navigation by recognition and give some results using frequency modulated sonar. Keywords: ultrasound, mobility aids, blindness, human interface 1. BACKGROUND AND STRUCTURE OF PAPER Vision is by far the most important sense for most people, and trends in virtual reality and computer interfaces reflect this emphasis. Sighted people appreciate detailed images and are able to abstract relevant data from images with ease, and the challenge in virtual reality is not in abstracting the data but providing enough detail at sufficient speed.
    [Show full text]
  • Kibo HANDBOOK
    Kibo HANDBOOK September 2007 Japan Aerospace Exploration Agency (JAXA) Human Space Systems and Utilization Program Group Kibo HANDBOOK Contents 1. Background on Development of Kibo ............................................1-1 1.1 Summary ........................................................................................................................... 1-2 1.2 International Space Station (ISS) Program ........................................................................ 1-2 1.2.1 Outline.........................................................................................................................1-2 1.3 Background of Kibo Development...................................................................................... 1-4 2. Kibo Elements...................................................................................2-1 2.1 Kibo Elements.................................................................................................................... 2-2 2.1.1 Pressurized Module (PM)............................................................................................ 2-3 2.1.2 Experiment Logistics Module - Pressurized Section (ELM-PS)................................... 2-4 2.1.3 Exposed Facility (EF) .................................................................................................. 2-5 2.1.4 Experiment Logistics Module - Exposed Section (ELM-ES)........................................ 2-6 2.1.5 JEM Remote Manipulator System (JEMRMS)............................................................
    [Show full text]
  • Physiology of Decompressive Stress
    CHAPTER 3 Physiology of Decompressive Stress Jan Stepanek and James T. Webb ... upon the withdrawing of air ...the little bubbles generated upon the absence of air in the blood juices, and soft parts of the body, may by their vast numbers, and their conspiring distension, variously streighten in some places and stretch in others, the vessels, especially the smaller ones, that convey the blood and nourishment: and so by choaking up some passages, ... disturb or hinder the circulation of the blouod? Not to mention the pains that such distensions may cause in some nerves and membranous parts.. —Sir Robert Boyle, 1670, Philosophical transactions Since Robert Boyle made his astute observations in the Chapter 2, for details on the operational space environment 17th century, humans have ventured into the highest levels and the potential problems with decompressive stress see of the atmosphere and beyond and have encountered Chapter 10, and for diving related problems the reader problems that have their basis in the physics that govern this is encouraged to consult diving and hyperbaric medicine environment, in particular the gas laws. The main problems monographs. that humans face when going at altitude are changes in the gas volume within body cavities (Boyle’s law) with changes in ambient pressure, as well as clinical phenomena THE ATMOSPHERE secondary to formation of bubbles in body tissues (Henry’s law) secondary to significant decreases in ambient pressure. Introduction In the operational aerospace setting, these circumstances are Variations in Earthbound environmental conditions place of concern in high-altitude flight (nonpressurized aircraft limits and requirements on our activities.
    [Show full text]
  • 2011 Annual Report
    Rochester Center for Biomedical Ultrasound icrobu ng m bble c eeri ont gin ras en t a e ge su n is ts t t E s standin i ect g w ss IP ef av u io e f e W b e c S ld h s U a y F r h I S a ling wa M c p H ve w t a a s r o U e r c n g r g o R i n g e z o i n l F t a a g i s s t g a t i a a o A o l e m g n i m R i r a F y c n s p c i I c t o h n i s n y e n o i l n u o n i t n q t g h r e a m e e i a r r a r f d v a a - r p a h h e s d a u n c g b t c i u i c o u s u a l r t o u h l s u a r s u t g n i l o t c n i r i t s a c r s e o r e u r D t o n t c d n o a o a i t b a e r r c p s p c l i e t r s u a o c c o a u s n t i o c i t r a a t d i v i a a t c i o n e c f r o 2011Annual Report RCBU laboratories are advancing biomedical ultrasound across many topics in diagnostic imaging, ultrasound therapy, and fundamental acoustics.
    [Show full text]
  • The Imaging Sciences Ultrasound Department Experienced More Than
    This year’s annual report The Imaging Sciences summarizes progress from Ultrasound Department RCBU laboratories across experienced more than 5% diverse topics in biomedical growth in exam and patient ultrasound imaging and volumes in 2009; performing therapy. The cover and related over 20,000 exams. The stories inside this report unit continued to expand describe advances by RCBU its clinical coverage; adding members on novel applications more sonographer positions to of ultrasound for tissue manage the increased demand. engineering and regenerative In the spring of 2009, medicine. The RCBU continues GE’s newest platform, the Logic to advance the development of E9, was installed; replacing elastography techniques. Included within this report the existing Logic9 units. The new machines provide are highlights of innovations in sonoelastography and enhanced image quality and improved workflow; new techniques based on acoustic radiation force. This allowing sonographers to merge real-time ultrasound with year also marked the naming of the UR Hajim School of previously acquired CT, MR, or ultrasound images. Engineering and Applied Sciences. The University of Rochester Medical Center was The RCBU continues to play a prominent role represented by sonographers and physicians in education in clinical and technological advances in the use of nationally and internationally. As faculty for Armed ultrasound for diagnostic imaging and therapy. Nonlinear Forces Institute of Pathology, Washington DC, Dr. imaging techniques, sonoelastography, and ultrasound Rubens continued to teach courses on spleen, testis, contrast agents all have foundations from innovations scrotum, portal Doppler, and testicular Doppler. Drs. within RCBU laboratories. Highlights of the Eighth Bhatt, Dogra, Rubens, Strang, and Voci also participated International Conference on Ultrasonic Measurement as faculty at the Radiological Society of North America and Imaging of Tissue Elasticity are reviewed in this (RSNA), the American Institute of Ultrasound in Medicine report.
    [Show full text]
  • A Review of Parametric Acoustic Array In
    Applied Acoustics 73 (2012) 1211–1219 Contents lists available at SciVerse ScienceDirect Applied Acoustics journal homepage: www.elsevier.com/locate/apacoust A review of parametric acoustic array in air ⇑ Woon-Seng Gan a, , Jun Yang b, Tomoo Kamakura c a School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore b The State Key Laboratory of Acoustics and the Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China c Department of Communication Engineering and Informatics, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu-shi, Tokyo 182-8585, Japan article info abstract Article history: In this review paper, we examine some of the recent advances in the parametric acoustic array (PAA) Available online 15 May 2012 since it was first applied in air in 1983 by Yoneyama. These advances include numerical modelling for nonlinear acoustics, theoretical analysis and experimentation, signal processing techniques, implementa- Keywords: tion issues, applications of the parametric acoustic array, and some safety concerns in using the PAA in Parametric acoustic array air. We also give a glimpse on some of the new work on the PAA and its new applications. This review Parametric loudspeaker paper gives a tutorial overview on some of the foundation work in the PAA, and serves as a prelude to Directional sound beam the recent works that are reported by different research groups in this special issue. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction 2. Theoretical framework of the parametric acoustic array The discovery of the parametric acoustic array (PAA) has come a When two sinusoidal beams are radiated from an intense ultra- long way (almost half century ago) since it was first theoretically sound source, a spectral component at the difference frequency is analyzed by Westervelt [1] in 1963.
    [Show full text]
  • Vocal Stereotypy and Singing Behavior in Baiomyine Mice
    Journal of Mammalogy, 88(6):1447–1465, 2007 VOCAL STEREOTYPY AND SINGING BEHAVIOR IN BAIOMYINE MICE JACQUELINE R. MILLER* AND MARK D. ENGSTROM Department of Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, Ontario M5S 2C6, Canada (JRM, MDE) Department of Ecology and Evolutionary Biology, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada (MDE, JRM) We examined spectral features that characterize the highly stereotyped, repetitive vocalizations of New World baiomyine rodents. Although stereotyped vocal signaling, described as ‘‘song,’’ has been documented in Scotinomys (singing or brown mice), its occurrence was unknown in the sister taxon Baiomys (pygmy mice). We also recorded vocalizations of females, about which little information was previously available. Although examination of morphological and molecular data supports a close relationship between the 2 baiomyine genera, we identified song as a complex behavior that further underpins the monophyly of the Baiomyini. Both spectral and temporal features render these songs highly localizable, a characteristic of possible utility for courtship and other social behavior. The song of Baiomys is confined entirely to the ultrasonic spectrum, unlike that of Scotinomys, which uses a broader range of frequencies. The intensity, identity, and predictability of vocalization suggest that these songs are purposeful and carry information important for species identification. Key words: Baiomyini, Baiomys, rodents, Scotinomys, song, stereotypy, ultrasound, vocal behavior ‘‘Nothing would work in the absence of communication.’’ within calls and songs (Catchpole and Slater 1995; Clark and (Hauser 1997) Wrangham 1993; Gil and Slater 2000; Hohmann and Fruth Animals communicate diverse information using vocal sig- 1994; Lengagne et al. 2001; Mitani et al.
    [Show full text]
  • Ultrasound 1 Ultrasound
    Ultrasound 1 Ultrasound Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults and thus, 20 kHz serves as a useful lower limit in describing ultrasound. The production of ultrasound is used in many different fields, typically to penetrate a medium and measure the reflection signature or supply focused energy. The reflection signature can reveal details about the inner structure of the medium, a property also used by animals such as bats for hunting. The most well known application of ultrasound is its use in sonography to produce pictures of fetuses in the human womb. There are a vast number of other applications as well.[1] Ability to hear ultrasound The upper frequency limit in humans (approximately 20 kHz) is due to limitations of the middle ear, which acts as a low-pass filter. Ultrasonic hearing can occur if ultrasound is fed Approximate frequency ranges corresponding to ultrasound, with rough guide of some directly into the skull bone and reaches applications the cochlea through bone conduction without passing through the middle ear. It is a fact in psychoacoustics that children can hear some high-pitched sounds that older adults cannot hear, because in humans the upper limit pitch of hearing tends to become lower with age.[2] A cell phone company has used this to create ring signals supposedly only able to be heard by A fetus in its mother's womb, viewed in a sonogram (brightness scan) younger humans;[3] but many older people claim to be able to hear it, which is likely given the considerable variation of age-related deterioration in the upper hearing threshold.
    [Show full text]
  • Sound from Ultrasound: the Parametric Array As an Audible Sound Source
    Sound From Ultrasound: The Parametric Array as an Audible Sound Source F. Joseph Pompei B.S. Electrical Engineering, Rensselaer Polytechnic Institute, 1995 M.M. Music Technology, Northwestern University, 1997 Submitted to the program in Media Arts & Sciences, School of Architecture and Planning in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology June 2002 @Massachusetts Institute of Technology, 2002 All Rights Reserved i-A Author rogb in Media Arts & Sciences May 22, 2002 Certified by ProfessIr Barry Vercoe Program in Media Arts and Sciences Thesis Supervisor NAN Accepted by Andrew B. Lippman Chairperson Departmental Committee on Graduate Students MASSACHUSETTS INSTITUTE OF TECHNOLOGY JUN 2- 2003 LIBRARIES Sound From Ultrasound: The Parametric Array as an Audible Sound Source F. Joseph Pompei Submitted to the program in Media Arts & Sciences, School of Architecture and Planning on May 22, 2002 in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology Abstract A parametric array exploits the nonlinearity of the propagation medium to emit or detect acoustic waves in a spatially versatile manner, permitting concise, narrow directivity pat- terns otherwise possible only with physically very large transducer geometries. This thesis explores the use of the parametric array as an audible sound source, permitting audible sound to be generated with very high directivity compared to traditional loudspeakers of comparable size. The thesis begins with a review of basic underlying mathematics and relevant ap- proximate solutions of nonlinear acoustic systems. Then, these solutions are used to con- struct suitable methods of ultrasonic synthesis for low-distortion audio reproduction.
    [Show full text]