Distinguished Plenary Lectures

Development in urban sound environment: towards soundscape indices

Jian Kang
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Professor Jian Kang, FIOA, FASA, CEng, obtained his BEngArch and MSc from Tsinghua University and PhD from University of Cambridge. He recently joint UCL as Professor of Acoustics, after worked as Professor of Acoustics at the University of Sheffield since 2003. Previously he also worked at the University of Cambridge and the Fraunhofer Institute of Building Physics in Germany. He has worked in environmental and architectural acoustics for 30+ years, with 60+ engineering/consultancy projects, 70+ research projects, and 800+ publications. His work on acoustic theories, design guidance and products has brought improvements to the noise control in underground stations/tunnels and soundscape design in urban areas. He is Fellow of the UK Institute of Acoustics, and Fellow of the Acoustical Society of America. He chairs the Technical Committee for Noise of the European Acoustics Association, and EU COST Action on Soundscape of European Cities and Landscapes. He was awarded IOA Tyndall Medal 2008, and Peter Lord Award 2014, and he is recipient of the prestigious Advanced ERC Grant on Urban Soundscapes.

UCL Institute for Environmental Design and Engineering, The Bartlett,University College London (UCL),London WC1H 0NN, United Kingdom.

While in EU alone 80 million citizens are suffering from excessive environmental noise, the conventional approach, i.e. reduction of ‘sound level’, although much work has been carried out, does not always deliver the required improvements in quality of life. The growing field of soundscape is addressing this gap by considering sound environment as perceived, in context, with an interdisciplinary approach. However, soundscapes are hugely complex and measuring them as a basis for environmental design requires a step change to the discipline. This talk explores the need for developing ‘soundscape indices’ (SSID), in the movement from noise control to soundscape creation, adequately reflecting levels of human comfort. By analysing the soundscape design of urban open public spaces, the coherent steps for achieving this are also discussed, including characterising soundscapes by capturing soundscapes and establishing a comprehensive database; determining key factors and their influence on soundscape quality based on the database; developing, testing and validating soundscape indices; and demonstrating the applicability of the soundscape indices in the management of our sound environment.

Future Issues in the Field of Acoustics

Rama Bhat
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Rama Bhat is a Professor of Mechanical, Industrial and Aerospace Engineering at Concordia University, Montreal, Canada. He completed his Bachelor’s in Mechanical Engineering from Karnataka Regional Engineering College, Srinivasanagar (National Institute of Technology, Karnataka) in 1966, and his M.Tech. and Ph.D. in Mechanical Engineering from IIT Madras, India, in 1968 and 1972, respectively. Dr. Bhat’s research area covers Mechanical Vibrations, Vehicle Dynamics, Structural Acoustics, Rotor Dynamics, Dynamics of Micro-Electro-Mechanical Systems. He has trained more than 20 Ph.D. students in these areas since he joined the Department in 1979. He is a Fellow of the Canadian Society for Mechanical Engineering, Engineering Institute of Canada, American Society of Mechanical Engineers, Institution of Engineers (India). He served as the President of Canadian Society for Mechanical Engineering in 2004-2006. He served as the Vice Provost at Concordia University in 2004-2008. He has been awarded the prestigious NASA Award for Technical Innovation for his contribution in developing “PROSSS—Programming Structured Synthesis System”. Dr. Bhat proposed the use of Boundary Characteristic Orthogonal Polynomials for use in the Rayleigh Ritz Method in 1985.

Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, Canada

Acoustics is the vibration of air particles. The air particle environment provides the stiffness property depending on the nature of packing of the air particles and the density of air provides the necessary mass in order to cause vibration of air particles. Most of the time, the vibrations are initiated by the structures containing the air particles and hence most of the time sound is caused by the fluid structure interaction. Acoustics takes the characteristics of the fluid and the structure containing the fluid. Hence the field of acoustics becomes quite vast depending on the generation, propagation and receiving of sound. The issues in acoustics research are hinged on these three interactive phenomena. Technology influences all the above three aspects and the field of acoustics and progress in research in these areas generally define the major issues in acoustics research. The following is an attempt to expand on the three aspects of acoustics and define the current and future issues in the field of acoustics. The issues include structural acoustics as in pressure vessels, piping systems, panels used in partitions, combustion noise, fluid structure interaction such as in turbine noise due to flow of pressurized gasses, blade vibrations in fluid flow environments, aeroelasticity of aircraft wings and helicopter rotors, drilling noise in machine shops, mining. Ultrasonic drilling is a done under the influence of ultrasound environment. Advances in micromechanics and nanomechanics have opened up an entirely new field of acoustic sensing to obtain many hitherto unexploited areas such as sound health monitoring of large industrial systems, environmental acoustics, community noise, building acoustics and sound conditioning of large halls, acoustic mapping of large structures and environmental noise scattering, etc. Medical acoustics is an extremely vast area including bioacoustics. Manufacturing environments have many uses such as condition monitoring, better design by understanding noise generation and propagation etc. Some recently emerging specific applications are: Cell separation using their response and behavior to acoustic vibrations in a microfluidic device, distributed acoustic sensing as a result of miniaturized and reliable acoustic microphone sensors, medical acoustics such as in ultrasound imaging, manufacturing applications such as in ultrasonic drilling, in building acoustics with improved absorption materials and sound conditioning capabilities, in musical acoustics with improved analysis capabilities to understand music perception etc. Overall it is a repetitive and iterative process with innovation and research driving the applications and enhancement of analysis and measurement and recording. It should be kept in mind that acoustics has many facets and containing it within the framework of a limited vocabulary is difficult and is an impossible task. However, the purpose of this talk is to sensitize the way in which research drives the analysis and measurement and processing of sound, and vice versa. Future issues in the field of acoustics emanate from the current issues using new developments in technology.

Acoustic Black Holes: Recent Developments and Applications in Vibration Control

M.G. Prasad
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M.G. Prasad is Professor Emeritus of Mechanical Engineering at the Stevens Institute of Technology. In his specializationareas of acoustics, vibrations and noise control, Dr. Prasad has published more than 100 publications in journals, conference proceedings and encyclopedias. He has received several awards for his papers. He has presented several invited papers in national and international conferences. He has been a director in the Institute of Noise Control Engineering (USA). He was the general chairman of NOISE-CON 91. He has served as UNDP expert for noise control projects. He is a consultant for several industries. Prof. Prasad was the recipient of 2015 Outstanding Educator Award by the Institute of Noise Control Engineering (USA). Dr. Prasad is a Fellow of four professional societies namely the American Society of Mechanical Engineers, the Acoustical Society of America, the Acoustical Society of India and Institute of Noise Control Engineering (USA). He received the 2017 Albert Nelson Marquis Lifetime Achievement Award from Who’s Who Publication Board.

Noise and Vibration Control Laboratory Department of Mechanical Engineering Stevens Institute of Technology Hoboken New Jersey 07030

Control of vibration and sound radiation from structures is very important in design of quieter mechanical systems. Recently a geometrical modificationfordesign of structures by embedding “Acoustic Black Holes” is used to control vibration and hence sound radiation. An acoustic black hole is a power-law tapered profile to reduce phase and group velocities of wave propagation to zero. Also, the vibration energy at the location of an acoustic black hole increases due to the gradual reduction of thickness. The major applications of this passive structural modification are many namely damping of vibration, noise reduction and vibration energy harvesting. The damping of vibration is achieved by placing damping material at the locations of acoustic black holes where vibration energy are concentrated. The suppression of structural vibration reduces sound in the near field which then results in noise reduction. The recent developments in vibration energy harvesting is based on the use of piezoelectric material as transducer to produce electrical output. In the case of vibrating structures, piezoelectric material is used where the acoustic black holes are embedded.As the vibration energyat these locations is increased which then yields increased electrical energy output for harvesting. This presentation includes recent developments in theory and applications of acoustic black holes to structural vibration control, noise reduction and energy harvesting.

The use of time reversal for source detection, defect localisation and perceptive structures

Jean-Louis Guyader
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Jean-Louis Guyader is presently Emeritus Professor at INSA, the National Institue of Applied Sciences in Lyon, France. He was the former Director of the Acoustics and Vibration Laboratory of INSA and founded in 2011 a small company, SONORHC, working on applications of vibroacoustics to engineering problems. His research focuses on vibration and acoustics, fluid-structure interaction in heavy and light fluids, inverse acoustics problems, theoretical methods for medium frequency vibro-acoustics problems, metamaterials and time reversal application in structures. He conducted numerous industrial applications of his researches in the fields of aeronautics, automotive industry, buildings and underwater military problems. He is Fellow of the Acoustical Society of America and of the International Institute of Acoustics and Vibration. He got the Chavasse prize and the Medal of the French Acoustical Society. He wrote two books and participated in several chapters of handbooks and collective books

Laboratoire Vibrations Acoustique, INSA de Lyon , 25 bis Avenue Jean Capelle, Villeurbanne 69621– France

Time Reversal (TR) concept is based on the symmetry of vibrations and acoustics phenomena associate to direct end reversed time. The main consequence of this time symmetry is the possibility of creating, from a measured response, time-reversed waves travelling from the measurement locations to the place where the primary waves were created. In the lecture, bases and limitations of Time Reversal concept are presented. Contrary to the standard inverse method, no regularisation is needed. Applications in biomechanics, military purposes and ultrasonics have been developed in the literature; this lecture focuses on engineering applications in the field of acoustics and structural vibration. The phenomenon of focalization is presented experimentally, and it is shown that, contrary to standard inverse problems for source detection, structural complexity renders Time Reversal technique more efficient. The automotive industry is a field of interest for source detection. The application of TR technique to detect vibro acoustic sources responsible for the noise produced in a car in operating conditions is of major interest. As an example, with TR technique one can clearly detect if the noise is coming from the airborne or structure-borne path, results on this case are presented. A second application of TR, is defect detection: when a structure has no defect, playing recorded time-reversed signals produce focalization of vibrations at primary source locations when the structure has defects the wave propagation travel is modified, and the focalization is no more observed, indicating the presence of a defect. Results obtained on a wind turbine blade are presented. A third application is related to the concept of perceptive mechanical media that can detect if a modification is occurring in its environment. This opens a gate to a lot of applications, in particular, the communication with tactile structures. Some experimental results .

Synthetic aperture sonar for sub-bottom imaging; possibilities and limitations.

Manell Zakharia
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specialist in: Underwater Acoustics, Sonar Systems & Signal Processing

Professor at French Naval Academy. Chargé de Mission, Development and Partnership Division, since 2017. Professor at ENSAM Paris 2016. International Technical Expert, French Embassy in India, Project officer, Indo-French collaboration with Indian Institute of Technology, Jodhpur 2013-2015. Professor at ENSAM (2012). Visiting Scientist at NATO/NURC- Founder & Director of CORALL: Centre for Ocean Research and Advanced Learning in Liguria (2009-2011). Professor at French Naval Academy (2001-2009). Founder and Director of LASSSO (acoustics and sonar) laboratory (1990-2001).

Honorary Fellow of the ASI, Acoustical Society of India (2012). Award of the EAA, European Acoustics Association (2011). National Medal of the SFA, French Acoustical Society (2010). Fellow Member of the IOA, Institute of Acoustics (UK, 2010). Senior Member of the IEEE, Institute of Electrical and Electronics Engineering (2005). Fellow Member of the ASA, Acoustical Society of America (2004).

Chairman of 9 conferences & workshops. Participation to 79 organisation & technical committees: Co-chair of Acoustics 2013 New Delhi (joint Indo-French Conference). Co-chair of ACOUSTICS’08 PARIS (joint SFA-EAA-SFA conference). IEEE/OES: Technology Committee co-chair (underwater acoustics, since 06). Acoustical Society of America: ASA Technical Committee on Acoustical Oceanography (2000-2001). 02-07: Program Director of ERASM, French network on education and research in underwater acoustics. 02-06: Responsible of imaging & inversion for “waves” Research group at the National Research Centre. 01-03: Deputy-Director of IRENAV and head of Underwater Acoustics Group. 90-00: Head of Laboratoire d’Acoustique, Systèmes, Signaux et Sonar LASSSO/CPE, Lyon. EAA, European Acoustics Association, Past Director: 99-01, Executive Director: 96-99. SFA, French Acoustical Society, President (92-94, 94-96), Vice-President (91-92).

HDR : Habilitation diploma, November 2000, INSA Lyon. PhD in acoustics, University of Aix-Marseille, June 1982. Masters in Acoustics: University of Aix-Marseille, 1979. Engineering degree in physics and electronics: ICPI Lyon 1978.

25 Publications in international Journals, 3 outreach articles, 9 Participations to books and 3 Book editing. 148 Publications in conferences, 231 Internal and contract reports.

17 PhD Thesis, 31 Master thesis & more than 70 Masters projects (masters in engineering). OTHER Languages: Fluent (reading & writing) in French, English and Arabic; beginner in Italian Hobbies: contemporary arts, music (jazz, blues), photography, sightseeing.

Scientific in charge of 12 European grants; Coordinator of 4 EC projects; Three of them are cited among the 36 examples of projects by the European Commission. 20 Contracts with the French Ministry of Defence (DGA, DCN, DRET, DCE). 18 Contracts with the French oceanography centre, IFREMER. 16 Other contracts (industrials + regional).

French Naval Academy / Development of Partnership BCRM Brest – École navale – CC600 29240 Brest Cedex 9, France

Aside all geophysical, geotechnical and offshore applications dealing with deep penetration in sea bottom (up to several kilometres), sub-bottom imaging for searching for objects deals with shallow sediment imaging (a few meters). Shallow penetration will lead to compromise frequency of a few kilohertz. Such an imaging is of interest in both military and civilian application domains: buried mine hunting, boulder detection, buried cables and pipelines as well as offshore industry components and underwater archaeology. The sedimentation of the sediment is highly variable between a recently buried object and the old buried ones. This will lead to very different properties of covering sediments. All these applications require a penetration of a few meters in the sediment and of a few centimetres in resolution. Synthetic aperture sonar, SAS, is a good candidate for such a situation as it breaks the link between the resolution and the array size. Nevertheless, the presence on the sediment may lead to a defocusing effect due to velocity changes (depending on the sedimentation history). First this defocusing effect will be investigated and several successful scenarios will be given for various situations. The second limitation of sub-bottom imaging is that one has to deal with volume reverberation (in opposition to surface reverberation in conventional sidescan sonar). Echoes from surface and volume reverberation may, of course, overlap in both time and angle.Thus, one will need to discriminate interface echoes from sub-bottom ones. Dual-band systems can be the solution for that problem. Results of dual-band imaging (cantered around about 10 and 100 kHz) will be shown with two geometries: conventional sidescan geometry and planar SAS).

Recent Developments and Future Issues in Underwater Acoustics.

Marcia J Isakson
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Marcia Isakson received a B.S. with a double major in engineering physics and mathematics from the United States Military Academy at West Point, New York, in 1992. Upon graduation, she was awarded the Hertz Foundation Fellowship. She earned her M.A. in physics from The University of Texas at Austin in 1994. From 1994 to 1997, Captain Isakson was stationed with the U.S. Army at Fort Hood, Texas. In 2002, she earned a Ph.D. from The University of Texas. Since 2001, she has been involved in research in underwater acoustics at the Applied Research Laboratories at the University of Texas (ARL:UT) at Austin. Her current research interests are the acoustics of ocean sediments, finite element modeling, acoustic scattering and propagation and high-frequency AUV-based sonar. Dr. Isakson has led the ARL:UT effort on numerous field tests measuring basic geo-acoustic properties of sediments and the effects of tidal fronts on high-frequency sonar. Dr. Isakson also teaches graduate-level underwater acoustics at the University of Texas at Austin. Dr. Isakson is currently serving as the past-president of the Acoustical Society of America where she has also served on the executive council and chaired several committees. She is a member of the governing board of the American Institute of Physics. Dr. Isakson has been designated as a Distinguished Lecturer of the IEEE Oceanic Engineering Society since 2010.

Applied Research Laboratories The University of Texas at Austin

The field of underwater acoustics has changed significantly sinceColladan and Sturm first measured the speed of sound in Lake Geneva. With the advent of computer technology, computational acoustics was born allowing for predictive models of acoustic propagation and scattering in complex environments. This field is currently burgeoning as evidenced by the creation of a new Technical Specialty Group at the Acoustical Society of America dedicated to cross-disciplined research in computational acoustics. These methods can now predict three-dimensional acoustics propagation and reverberation in complex areas using finite elements, spectral elements and parabolic equation methods. As the ocean became better understood and parameterized, describing the environment became increasingly important. This included understanding reflection and scattering from the ocean bottom and surface as well as scattering from discrete objects in the water column such as bubbles, suspended sediment and fish. In particular, understanding the different frequency responses of the water column scatterers aids in assessing sediment transport in rivers, tracking tidal events and determining fish populations. Lastly, as the field of underwater acoustics evolved, so did its applications. It can now be used to assess ecosystem health, distinguish first-year and multi-year Arctic ice, and understand tidal activity in riverine environments. The future of underwater acoustics remains as unbounded today as it did the day the Colladan and Sturm crouched in their boats measuring Lake Geneva. Due to fundamental laws of physics, acoustics will always be the primary tool for communication, remote sensing and environmental assessment in our rivers and oceans. We should develop our capabilities to monitor the health of the earth by quantifying underwater carbon capture, assessing coral reef health, and keeping track of the changing Arctic by continuing work on modeling and understanding acoustic propagation and scattering in complicated and complex environments.