Andy Piacsek

Full CV in PDF format

Educational Background

B.A., Physics, Johns Hopkins University, 1986
M.S., Acoustics, Penn State University, 1991
Ph.D., Acoustics, Penn State University, 1995

Teaching

Courses that I have taught over the past 10 years:

• PHYS 103 Physics of Musical Sound
• PHYS 111-113 Introductory Physics
• PHYS 181-183 General Physics
• PHYS 317 Modern Physics
• PHYS 342 Thermodynamics
• PHYS 361 Computational Physics
• PHYS 461 Advanced Computational Physics
• PHYS 489 Senior Assessment
• COTS 184 Conspiracy Theories (with Anthony Stahelski)
• DHC 280 Wide World of Sound (through the Douglas Honors College)
• MUS 611 Graduate Seminar in Music Pedagogy (with Bret Smith and Ralf Greenwald)

Research

My primary areas of interest and expertise are physical acoustics and musical acoustics. I am interested in waves of all kinds, from sound waves in a trumpet to sonic booms to tsunamis. that such disparate phenomena are united by similar mathematics is what makes the field of acoustics especially intriguing.

Another area of interest is the epistemological basis of science, the role of science and society, and how to improve scientific literacy and understanding among non-scientists. I am interested in the ways in which society develops its perceptions of science, including the perseverance of pseudo-scientific and unscientific beliefs. My main work in this area is developing curriculum at

the university level that specifically addresses our understanding of how science works and why this is important.

I operate the CWU Acoustics Research Lab located in Discovery Hall. Specialized equipment and capabilities of this facility include:

• Anechoic chamber (approximately 5 meters along each dimension) with an automated microphone positioning system and Labview data acquisition system
• Scanning laser doppler vibrometer (Polytec LSV-500) with macro lens
• National Instruments SeeSV-S205 Sound Camera
• Custom built 20cm x 20cm impedance tube
• A variety of GRAS measurement microphones (46AE, 46DD, 46AZ, 46AQ, 46BL)
• A variety of PCB accelerometers, force sensors, and modal impact hammers
• A variety of Labworks and Modal Shop shakers
• Svantek 971 and 979 type 1 sound level meters
• NI PXI portable data acquisition systems

Current projects with undergraduate students:

• The violin playing-in experiment.  A common belief among performers and builders of stringed musical instruments, especially violins, is that new instruments will sound “better” after being played for some time – in other words, that there is a “breaking in” or “playing in” process that occurs.  We are in the midst of an experiment to measure changes in the vibrational and acoustic response of a violin body that can be attributed to sustained mechanical excitation (i.e. many hours of playing).  We are working with three new violins with consecutive serial numbers: one is a control (left alone), one is being vibrated with a commercial product (the Tone Rite) that is placed on the bridge, and the third is being driven mechanically at the bridge with a source spectrum derived from standard violin repertoire.  The mechanical stimulus will occur 24/7 for several weeks, during which we periodically test all three violins: measuring bridge admittance with a laser vibrometer and sound radiation using microphones in an anechoic chamber.  Because we anticipate subtle changes in these measurements over time, it was important to determine our experimental uncertainty, which is the variability that we see from one measurement to the next, even on the same day.  We developed a way to quantify this variability, so that we can determine whether changes due to “playing in” are statistically significant.

• Investigate a noninvasive approach to monitoring intracranial pressure that utilizes subtle changes in the vibrational response of the skull.  Initially, we demonstrated that a spherical aluminum shell exhibits shifts in some resonance frequencies that are proportional to the internal pressure, regardless of whether the shell was filled with water or air.  With a COMSOL finite-element model of the pressurized shell, we confirmed that the frequency shifts are due to geometric nonlinearity, which is a property of curved plates. Current experiments seek to reproduce the effect with animal models (e.g. sheep heads) and human cadavers.

Other recent projects

• experimental and computational study of wave behavior in a tensegrity mast

• measuring and modeling wind turbine noise

• modeling sonic booms from maneuvering aircraft (funded by NASA)

Consulting projects

• Noise study for an automated car wash in Seattle, WA.  We took sound level measurements of an existing car wash operation in a gentrifying neighborhood; built a model using SoundPlan, using our data to calibrate the source level; ran the model with a variety of noise mitigation strategies; and prepared a report for our client.

• I was awarded a contract from the WA Department of Fish and Wildlife to conduct an acoustic study in support of proposed shooting range to be developed on state forest land.  We conducted sound level measurements with a variety of live munitions and developed a model with SoundPlan to predict the noise levels in the surrounding area for a variety of firing range layouts and noise mitigation strategies.

• Windrow Hotel ballroom.  A local developer engaged me and my PHYS454 Acoustics class to conduct an acoustic study of an existing ballroom in the former Elks Lodge in downtown Ellensburg, WA, that would be remodeled as part of a new hotel that was being constructed adjacent to the Elks building.  Students took reverberation time measurements, with and without a large number of padded chairs in the room.  In small groups assigned to different tasks, they researched the sound absorption properties of carpeting, movable wall drapes and window curtains, and panels suspended from the ceiling, then calculated how much each component would contribute to reducing the reverberation time.  I prepared a final report incorporating the students’ calculations that provided guidance on what treatments would most effectively provide a target range of RT values.

Selected Publications and Presentations

Articles in Refereed Journals  (* denotes undergraduate co-author)

• Rajendran, V., Piacsek, A., and Mendez, T., “Design of broadband Helmholtz resonator arrays using the radiation impedance method,” J. Acoust. Soc. Am., 151, 457-466 (2022). 
• Piacsek, A., *Taylor, R., and *Abdul-Wahid, S., "Resonance frequencies of a spherical aluminum shell subject to static internal pressure," J. Acoust. Soc. Am., 131 (6), pp. EL506-511 (2012).
• McDonald, B.E. and Piacsek, A., “Nonlinear Progressive wave Equation for Stratified Atmospheres,” J. Acoust. Soc. Am., 130, 2648-2653 (2011).
• Piacsek, A., “Atmospheric turbulence conditions leading to focused and folded sonic boom wavefronts,” J. Acoust. Soc. Am., 111, 520-529 (2002).
• Piacsek, A., “A 2D numerical solution for the evolution of shock profiles subject to wavefront focusing and diffraction.” Environmental Acoustics: International Conference on Theoretical and Computational Acoustics, vol. 2,  D. Lee and M. Schultz, eds., World Scientific (1994).

Conference Proceedings

• Lowery, S. and Piacsek, A.,  “A quantitative assessment of uncertainty in the measurement of violin impact response,” Proc. Mtgs. Acoust. 46, 035003 (2022). 
• Piacsek, A., “Name that timbre!  An interactive demonstraction for teaching concepts of harmonic content in musical sounds.” Proceedings of the 26th International Congress on Sound and Vibration, Montreal, Canada (2019).
• Piacsek, A. and Plotkin, K.,  “SCAMP: Application of Nonlinear Progressive-wave Equation to Sonic Boom Transition Focus,” Proceedings of 51st AIAA Aerospace Sciences Meeting, Grapevine, TX, paper 1064 (2013). ). [pdf]
• Piacsek, A., Locey, L., and Sparrow, V.,  “Time-domain modeling of atmospheric tubulence effects on sonic boom propagation,” Proceedings of the 29th AIAA Aeroacoustics Conference, Vancouver, BC, paper 3032 (2008).
• Locey, L., Sparrow, V., and Piacsek, A.,  “Sonic boom post processing to include atmospheric turbulent effects,” 29th AIAA Aeroacoustics Conference, Vancouver, BC, paper 3035 (2008).

Technical Reports

• J. Page, K. Plotkin, J. Salamone, A. Piacsek, V. Sparrow, K. Elmer, R. Cowart, D. Maglieri,  “Superboom Caustic Analysis and Measurement Program final report," NASA/CR-2015-218871, August 2015.

Other

• A. Piacsek,  “Communicating your research to journalists (and your relatives)," Acoustics Today, 16 (3), pp. 80-83 (2020).
• A. Piacsek, “Sound,” Tutorial article for Access Science, McGraw-Hill (2020).  Accessible online at

• A. Piacsek,  “Public Relations Committee overview," Acoustics Today, 14 (1), pp. 60-63 (2018).