The Importance of a Diverse Acoustics Toolbox
Friday, December 2, 2022, 4:00 p.m. Central Time
Dr. Theodore F. Argo
Applied Research Associates, Inc.
Littleton, Colorado
www.ara.com
Acoustics is a discipline spanning fundamental science to standardized industrial processes with impacts on everyday life. New applications of acoustics are continually developed to make our world safer and make us more secure through both government programs and industry initiatives. Researchers and technology developers must have a myriad of tools in their personal “toolbox” to consider new approaches to these sometimes critical human problems. Application of a variety of experimental and numerical tools in acoustics learned through the UT Acoustics program will be presented in diverse areas including: (1) hearing injury modeling based on shock tube measurements, (2) a software tool for prediction of underwater blast during decommissioning of oil wells, (3) a remote jet blast measurement system for evaluation of new technologies, (4) manipulation of aerosols using ultrasonic resonators, and (5) correlation of electromechanical hearing protection evaluation methods with human performance. The application of acoustics to each area will be presented including the experimental and modeling techniques used and the insight gained from each program. How the results of these programs are translated to the sponsor and to the public will also be discussed for each program type.
Information Technology Product Acoustical Thresholds
Friday, November 11, 2022, 4:00 p.m. Central Time
Chris E. Peterson and Amrita S. Maguire
Dell Technologies
Round Rock, Texas
Dell.com
Acoustics is an important design area for Information Technology (IT) products. Hard disk drives fail to write when they are shaken by sound from air movers. Humans become annoyed or suspect something is wrong when their devices make unexpected sounds. In order for an engineer to scope solutions and tradeoffs for these types of problems, appropriate acoustical metrics and respective targets must be determined. In this seminar, the presenters will share the complementary roles of Acoustical Engineering and Human Factors Engineering. They will review approaches taken to characterize and deliver product acoustical thresholds and discuss successes and challenges encountered along the way.
Learning Speech Representations with Multimodal Self-Supervision
Friday, November 4, 2022, 4:00 p.m. Central Time
Professor David Harwath
Department of Computer Science
The University of Texas at Austin
https://www.cs.utexas.edu/people/faculty-researchers/david-harwath
Humans learn spoken language and visual perception at an early age by being immersed in the world around them. Why can’t computers do the same? In this talk, I will describe our ongoing work to develop methodologies for grounding continuous speech signals at the raw waveform level to natural image scenes. I will first present self-supervised models capable of discovering structure (words and sub-word units) in the speech signal. Instead of conventional annotations, these models learn from correspondences between speech sounds and visual patterns such as objects and textures. Next, I will demonstrate how these models can be leveraged to learn cross-lingual correspondences. Finally, I will show how these representations can be used as a drop-in replacement for text transcriptions in an image captioning system, enabling us to directly synthesize spoken descriptions of images without the need for text as an intermediate representation.e
Modeling of Focused Shear Wave Beams for Linear and Nonlinear Elastography in Muscle Tissues
Friday, October 28, 2022, 4:00 p.m. Central Time
Dr. John M. Cormack
Department of Medicine
University of Pittsburgh
Multi-modality Biomedical Ultrasound Imaging Lab
The shear modulus of soft tissues is a useful biomarker for the evaluation of soft tissue pathology such as that found in breast lesions, liver diseases, and musculoskeletal disorders. Ultrasound shear wave elastography (SWE) is a noninvasive technique for estimating the tissue shear modulus by observing the propagation speed of shear waves in the tissue. Whereas tissues like breast or liver can be considered isotropic, the fibrous structure of skeletal muscle makes it anisotropic with one preferred direction (the fiber direction) and therefore it must be modeled as transversely isotropic (TI). This talk gives an overview of shear wave propagation physics in TI soft tissues. New results regarding nonplanar (diffracting) and nonlinear (large amplitude) propagation are highlighted. Beginning with linear theory, a new model for diffracting shear wave beams in a TI soft solid is introduced, and preliminary experimental results in gel phantoms are presented. Nonlinear effects in plane shear wave propagation are then discussed, where a nonlinear wave interaction unique to TI tissues compared to the isotropic case is highlighted. The ability to exploit this unique interaction for elastography in vivo is explored by considering both nonlinear and diffraction effects simultaneously.
“You Shoulda Been Here Last Night”:
Adventures in Environmental Noise Measurement
Friday, October 21, 2022, 4:00 p.m. Central Time
David A. Nelson
Principal Consultant
Nelson Acoustics
Bella Vista, Arkansas
www.nelsonacoustical.com
A simple enough concept: take your sound level meter to someone’s property and measure a noise they find intrusive. In practice this can be extremely challenging because many factors are unpredictable and/or outside your control. In most cases you are informed upon arrival that the noise at present is not the same noise that caused you to be called out in the first place—it may seem like you’re trying to “capture lightning in a bottle”. This seminar will draw on recent experiences with remote long-term environmental noise measurements, incorporating some audio examples. We’ll discuss variability of the source, the atmosphere, and the local environment, time- and frequency-domain methods for distinguishing intrusive noise from the ambient background, as well as real-time monitoring, data handling, and special equipment considerations.
Source-Filter Interactions in Vocal Tremor and Vibrato
Friday, October 14, 2022, 4:00 p.m. Central Time
Professor Rosemary A. Lester-Smith
Department of Speech, Language, and Hearing Sciences
The University of Texas at Austin
https://slhs.utexas.edu/faculty/rosemary-lester-smith
https://slhs.utexas.edu/research/ut-voice-lab
The neurogenic voice disorder vocal tremor and the singing technique vocal vibrato involve rhythmic modulation of fundamental frequency and intensity. Modulation of fundamental frequency is primarily caused by oscillation of laryngeal structures; however, modulation of intensity may be caused by oscillation within the respiratory system, larynx, or vocal tract. In addition, interactions between the laryngeal source and the vocal tract filter may contribute to modulation of intensity. Standard acoustical assessments of voice cannot differentiate the physiological sources of intensity modulation because microphone signals represent a combination of source and filter features. However, a vibration sensor applied to the neck-surface may capture features of the source before vocal tract filtering. This presentation will describe recent studies comparing microphone and neck-surface vibration sensor signals in simulated vocal tremor and singers producing vibrato to characterize source modulations and source-filter interactions, and to investigate the usefulness of this approach in clinical assessment of vocal tremor.
Lung Sounds in Respiratory Diagnosis
Friday, October 7, 2022, 4:00 p.m. Central Time
Professor Ilene J. Busch-Vishniac
Chief Innovation Officer and Chief Operating Officer
Sonavi Labs, Inc.
Baltimore, Maryland
https://sonavilabs.com
Listening to lung sounds through a stethoscope has long been part of every medical checkup, but traditional stethoscopes (ironically called acoustic stethoscopes) produce distorted sound and make it difficult to distinguish breath sounds from heart beats. They also fail in noisy environments. This talk demonstrates how lung sound monitoring and analysis can be greatly improved by using a digital stethoscope with artificial intelligence to establish patterns that correlate with lung abnormalities. This permits telehealth appointments to be used in listening to lung and heart sounds in real time, and also allows for the management of the chronic lung diseases of patients, such as asthma and COPD, from home. The scientific basis for this approach is presented in this talk.
Use of Sound and Vibration for Fault Detection in Wind Turbines
Friday, September 30, 2022, 4:00 p.m. Central Time
Michael E. Stone
RWE Renewables Americas, LLC
Austin, Texas
https://americas.rwe.com/
Unexpected downtime of power generation assets can lead to significant revenue losses not just through lost energy sales, but through disruptions to asset operations having to staff and manage unplanned repairs. To combat this, operators of critical equipment are increasingly turning to advanced Condition Monitoring Systems (CMS) to monitor asset health in an effort to predict when specific components will fail so they can plan accordingly. Vibrational CMS has proven to be a leading technology for detecting the early onset of component failure in wind turbines, sometimes years in advance. Leveraging accelerometers, microphones, and other sensors, acoustic snapshots can be taken of the turbine drivetrain, where the use of various signal processing techniques can identify failing components. This seminar will introduce the basics of predictive maintenance and vibration-based CMS, and discuss the unique challenges that the technology faces in the wind industry.
Characterization of Loudspeaker Parameters and a DELTAEC Model of a Bass-Reflex Enclosure
Friday, September 23, 2022, 4:00 p.m. Central Time
Professor Steven L. Garrett (Retired)
Graduate Program in Acoustics
The Pennsylvania State University
https://www.acs.psu.edu/
A typical electrodynamic loudspeaker is a nearly ideal realization of a damped, driven, simple harmonic oscillator. The speaker’s voice coil can provide a controllable force when driven by an electric current or can act as a sensitive velocity transducer. As such, the electromechanical parameters that characterize the suspension stiffness, moving mass, mechanical resistance, and transduction coefficient (i.e., product Bℓ) of a speaker can be accurately determined using simple physical measurements and linearized least-squares fitting. Those loudspeaker parameters will be used to analyze a bass-reflex loudspeaker enclosure that includes modeling of the frequency-dependent resistance and inertance of the damping in the port. The behavior of those coupled harmonic oscillators (i.e., the electrodynamic loudspeaker and the Helmholtz resonator that contains the loudspeaker) will be determined by use of DELTAEC software, which is available for download worldwide at no cost.
Spatial Nonlocality and Its Effects on the Scattering Characteristics of Acoustic and Elastic Media
Friday, September 16, 2022, 4:00 p.m. Central Time
Dr. Nathen Geib
Applied Research Laboratories
The University of Texas at Austin
https://wwwext.arlut.utexas.edu
Reciprocity is the principle in the study of wave propagation that states that given a source and a receiver in a linear domain, switching their locations will not affect the received signal. Systems that break reciprocity have received substantial attention over the last decade for their potential applications in noise and vibration control, cloaking, and diagnostic imaging. Presented here is an investigation of how action at a distance affects the scattering characteristics of acoustic and elastic media. We focus on how such a nonlocal coupling, imposed by transmitting a sensed disturbance at one location through a controller to an actuator at a separate location, can be used to strongly break reciprocity in linear acoustic and elastodynamic systems. Because their separation distances are subwavelength, each sensor-actuator pair can be treated as a single unit cell of a larger metamaterial. For a single acoustic unit cell, we discuss the mechanisms by which reciprocity is broken and the conditions for system stability. We then discuss the strong coupling between adjacent unit cells in systems with multiple cells, and the implications that such coupling has on both system performance and stability. Next, we show how nonlocal coupling in an elastodynamic system results in the highly nonreciprocal transmission of flexural waves. Finally, we discuss future directions of this work.
Research at Applied Research Laboratories: A Brief History and Current Work in Acoustics
Friday, September 9, 2022, 4:00 p.m. Central Time
Dr. Karl B. Fisher
Executive Director
Applied Research Laboratories
The University of Texas at Austin
https://wwwext.arlut.utexas.edu
Applied Research Laboratories, The University of Texas at Austin (ARL:UT) is a Department of Defense University Affiliated Research Center (UARC). In parallel with its UARC mission, ARL:UT advances the mission of our parent university of education, research, and public service. Through fundamental research, innovative science, and applied engineering, ARL:UT makes significant contributions in support of national security. We are proud that many of our contributions have a direct and positive impact for those who protect us through their military service.
Universities have long played a critical role in our nation’s defense. A brief history of ARL:UT will be provided, followed by a general overview of the current research portfolio. The talk will include examples of acoustics-related research covering basic research, prototyping, and the transition of capabilities in support of national security.
Calling Strategies in Túngara Frogs: Multiple Influences Within Multi-Species Communication Networks
Friday, April 29, 2022, 4:00 p.m. Central Time
Luke C. Larter
Department of Integrative Biology
The University of Texas at Austin
https://sites.cns.utexas.edu/ryan-lab
Animal signals take a variety of forms and play an important role in courtship in many species. Though often studied as one signaler sending a signal to a single receiver, in reality most signals are sent and received within complex communication networks. These networks contain other members of the signaler’s species, both intended receivers and rival signalers, as well as individuals of other species such as predators and parasites that eavesdrop on signals to locate signalers as prey. I will discuss my research into how the calling strategies of male túngara frogs have been shaped by the nature of the communication networks they call within. Males call in dense choruses containing many other calling males. This produces issues relating to call interference among callers which can detrimentally affect call attractiveness. I suggest that males’ tendency to produce increasingly elaborate calls in denser choruses acts to mitigate the attractiveness costs of such interference. Additionally, I suggest that the modulation patterns of call acoustic parameters across calling episodes of túngara frogs have been shaped by the pros and cons of calling within dense choruses, when these choruses are nested within multi-species communication networks containing eavesdropping enemies such as predators and parasites.
Ultrasonic Inspection of Lithium-Ion Batteries for Damage Detection and Prevention of Thermal Runaway
Friday, April 15, 2022, 4:00 p.m. Central Time
Tyler M. McGee and Barrett J. Neath
Applied Research Laboratories
The University of Texas at Austin
https://wwwext.arlut.utexas.edu/
Accurately monitoring the safety of lithium-ion batteries to prevent a thermal runaway (TR) event is of utmost importance, especially in high-power applications such as electric vehicles. The fire caused by a lithium-ion battery is particularly difficult to extinguish because it continuously emits highly flammable gas and burns at an extremely high temperature. Current battery management systems (BMS) only monitor safety by measuring voltage, current, and temperature for collections of cells, known as battery modules. Because the BMS operates on the module-level, current BMS inputs can fail to predict a TR event, which often begin with individual cell failures. We report initial studies on the use of ultrasonic wave measurements to enable early detection of cell damage while simultaneously monitoring voltage, current, temperature, and mechanical clamping force and varying the electrical, mechanical, and thermal loading conditions. We monitor time- and frequency-domain features of the acoustic signals transmitted along two propagation paths for excitation frequencies between 0.1–1 MHz and show correlations between changes in time-of-flight and signal amplitude with variations in electrical, thermal, and clamping force when cells are subjected to thermal abuse scenarios. Early indicators of damage in the ultrasonic signals are presented, compared with other detection metrics, and discussed with respect to propagation paths and known damage mechanisms in lithium-ion batteries.
A Taste of Task Force Ocean at ARL:UT
Friday, April 8, 2022, 4:00 p.m. Central Time
Robert T. Taylor, Christopher A. Stockinger, and Ivana Escobar Casterlin
Applied Research Laboratories
The University of Texas at Austin
https://wwwext.arlut.utexas.edu/
Task Force Ocean (TFO) was established in March 2017 by the U.S. Navy to advance Navy-relevant ocean science through strengthened partnerships with academia and the private sector. This seminar highlights three research projects from the TFO at the Applied Research Laboratories at the University of Texas at Austin (ARL:UT). The first project examines regions of the world’s oceans where oceanographic models fail to capture the vertical structure of temperature and salinity, missing important features that influence acoustic propagation. This work presents a method for populating these regional underwater sound speed environments from a sparse set of measurements using an interpolation scheme. The second project investigates low frequency ambient noise resulting from wind-generated sources. An empirical model that predicts ambient noise from overhead wind speed is presented and initial developments of a long-range source level model are discussed. The third project considers constraining a general ocean circulation model through available acoustic observations. Through the use of a dynamically consistent inversion framework, a regional ocean model is proposed to assimilate acoustic travel times and explore their sensitivities to the hydrographic state.
Contemporary Acquisition and Interpretation Procedures for Borehole Acoustic Measurements
Friday, April 1, 2022, 4:00 p.m. Central Time
Professor Carlos Torres-Verdin
Hildebrand Department of Petroleum and Geosystems Engineering
The University of Texas at Austin
https://sites.utexas.edu/carlostorresverdin/
Borehole acoustic measurements are widely used to assess in-situ elastic and mechanical properties of rocks continuously along drilled wells. The borehole environment places significant constraints on the rock properties that can be measured and/or estimated from various detectable dispersive and non-dispersive acoustic/elastic waves modes. The advent of high-angle and horizontal wells in the exploration and development of subsurface fluid resources has also brought about formidable technical challenges concerning omnipresent anisotropy and logging-while-drilling measurements for subsurface well navigation. Additionally, borehole ultrasonic measurements are being used not only to assess the integrity of cement bonding behind steel casing but also to provide reflectivity images around the borehole for high-definition descriptions of spatially complex rocks. Relatively newer measurements include time-lapse monitoring methods for behind-casing evaluation of hydrofracturing operations, including monitoring with fiber-optics distributed acoustic sensing (DAS).
This presentation will introduce the basics of modern borehole acoustic sensing in open and cased-hole operations, the corresponding measurements and their interpretation. Emphasis will be placed on how the measurements are integrated with rock physics models to estimate relevant engineering products for drilling, rock mechanics, geohydrology, hydrocarbon reservoir assessment, CO2 sequestration, and geothermal resources.
Exploring Tinnitus: Central Inhibition
Friday, March 4, 2022, 4:00 p.m. Central Time
Matthew Randal
Department of Speech, Language, and Hearing Sciences
The University of Texas at Austin
https://slhs.utexas.edu/
Tinnitus is defined clinically as the perception of sound for which there is no external source. Primarily presenting in humans following a traumatic acoustic event, it is less commonly observed within patients with clinically normal hearing. However, there are indeed patients who have no clinical evidence of peripheral dysfunction (e.g. hearing loss) yet still present with chronic tinnitus. It is a reasonable hypothesis to suspect that decreased central inhibition may be a reason that patients with normal hearing still experience tinnitus. EEG may be used to obtain cortical auditory evoked potentials (CAEPs) and can assess the integrity of central inhibition while potentially revealing the role of inhibition in tinnitus. In 2018, Campbell et al. revealed impaired gating function via EEG-obtained CAEPs within a test group of normal hearing adults with mild tinnitus. Our hypothesis is that abnormal central mediation of gating identified through EEG measures could be useful clinically to identify patients with normal hearing who are susceptible to developing tinnitus.
Acoustical Consulting & The Acoustics of Industrial Metal Buildings
Friday, February 25, 2022, 4:00 p.m. Central Time
Dr. Tim Simmons
Director of Industrial Acoustics
United Steel Structures, Inc.
https://www.ussi.com
In the first part of this seminar, I will briefly discuss my acoustical consulting experience. During prior work comprising over 15 years as an acoustical consultant, I completed a variety of projects in multiple acoustical domains. This part is aimed at students and those interested in getting a flavor for two job paths available in the large world of acoustics. Currently, as Director of Industrial Acoustics at United Steel Structures, Inc. I am focused squarely on the acoustics of industrial metal buildings and the environments that surround them. The second part will be “metal buildings 101;” metal building components and construction will be described and I will clarify what is meant by “industrial metal buildings.” In the final segment, acoustical challenges that are unique to industrial metal buildings will be described. Key considerations are the use of corrugated metal, perforated metal, structural framing, and large sound source size relative to room volume.
A Sampling of Acoustics Research at CRREL
Friday, February 18, 2022, 4:00 p.m. Central Time
Dr. Michael B. Muhlestein
Cold Regions Research and Engineering Laboratory (CRREL)
US Army Engineer Research and Development Center
https://www.erdc.usace.army.mil/Locations/CRREL/
The Cold Regions Research Engineering Laboratory (CRREL), part of the US Army Engineer Research and Development Center, hosts a diverse set of research expertise including acoustics. In the five years I have worked at CRREL I have been able to participate in many different projects. In this talk I will elaborate on three projects, two completed and one in progress. The first project focused on predicting sound propagation in forests, where I contributed an analytical framework to describe the reverberant sound field due to a point source. The second project aimed to create a structure to temporally disperse acoustic energy from impulsive sources, which had the opportunity to lead the design process. The final, and ongoing, project is focused on using linear acoustic metamaterial methods to control the nonlinear evolution of high-amplitude sound propagation in air. I will present our progress on this last project as well as a preliminary structure design to accelerate shock formation in air. These projects give a taste of the quality and diversity of acoustics-related basic research that occurs at our laboratory.
Using Helical Guided Waves for the Condition Assessment of Cylindrical Structures
Friday, February 11, 2022, 4:00 p.m. Central Time
Stylianos Livadiotis
Department of Civil, Architectural, and Environmental Engineering
The University of Texas at Austin
https://sites.google.com/view/ssrg/
Pipelines are a vital component in the gathering, transmission, and distribution networks of oil and gas products around the globe. Many pipeline accidents are reported each year in the US with corrosion being one of the most common forms of failure causing significant wall-thickness and pressure loss. This work investigates the use of active and passive ultrasonic methods to localize, monitor, and quantify corrosion in steel pipelines. This is achieved by exploiting the helical guided ultrasonic waves (HGUW) in combination with numerical modeling and advanced data processing techniques. A key feature of the HGUW is the ability to use a small number of permanently attached sensing units with the capacity to perform both defect localization and tomography. The presentation will discuss theoretical, numerical, and experimental aspects of the HGUW for pipeline health monitoring as well as their limitations.
Additive Manufacturing Enables New Ideas in Acoustics
Friday, January 28, 2022, 4:00 p.m. Central Time
Dr. Christina J. Naify
Applied Research Laboratories
The University of Texas at Austin
https://wwwext.arlut.utexas.edu/
Additive manufacturing, also known as 3D printing, is a manufacturing process by which materials are selectively added to build an object. It can be helpful to contrast this approach to subtractive manufacturing, such as cutting and drilling, where material is selectively removed from a material to create an object. Additive manufacturing has expanded greatly in the last 10 years and unsurprisingly many who study acoustics are using the technology to further their research. In this seminar, I will highlight the intersecting fields of additive manufacturing and acoustics. I will begin with a brief history and an overview of the basic technologies and workflow of some common additive approaches. The bulk of the seminar will comprise of case studies for additive approaches applied to a wide variety of acoustical areas including but not limited to musical acoustics, acoustic transducer fabrication, and acoustic metamaterials. Finally, I will highlight some of the challenges associated with using additive as a manufacturing technique.