What We Do

The Acoustics Department studies the propagation and scattering of sound. Historically our primary focus has been the ocean and on structures in the ocean using theory and numerical modeling backed by ocean experiments. In the next ten years we plan to strengthen our non-ocean related research efforts.

Our research spans the frequency range from a few hertz to hundreds of kilohertz. We seek to understand and quantitatively predict propagation and scattering (the ‘forward’ problem). These predictions require detailed knowledge of the environment and the material properties of targets. To measure the ocean environment, we collaborate with physical, biological and geophysical oceanographers. Those same collaborations are essential to our development of acoustical oceanography techniques (the ‘inverse’ problem).

A forward problem in environmental acoustics asks, "Given the environment, what is the received signal?" High fidelity forward models then allow us to address the inverse problem, "Given recorded acoustic data, what is the environment?" Solving the forward problem requires a combination of physical understanding, theoretical development, and analytic and numerical modeling. The inverse problem offers many challenges as well, since it may be nonlinear, non-unique, and sensitive to uncertainty in environmental properties and the details of the acoustic data.


  • Acoustic propagation and scattering from volume heterogeneities and surface roughness
  • Undersea acoustic communications
  • Remote sensing of the environment
  • Acoustical oceanography
  • Scattering from objects deployed in the ocean
  • Ambient noise in air and underwater environments
  • Measurement and control of underwater industrial noise
  • Arctic acoustics

Affiliate Members

Philip Marston, WSU

What's New?

TREX13: Target and Reverberation EXperiment 2013

This ocean acoustics experiment measured mid-frequency reverberation and the abilities to detect and classify unexploded ordnance and mine-like targets on the seafloor using synthetic aperture sonar in a shallow water environment off Panama City, FL.   More >>

History of Acoustics Research at APL-UW Six Decades of Acoustics Research at APL-UW, presented by Kevin Williams at the Acoustical Society of America meeting in Pittsburgh, PA, May 2015. (YouTube video)

Using Vector Sensors to Measure the Complex Acoustic Intensity Field David Dall’Osto and Peter Dahl (PPT 37 MB)

Acoustic Color of Mines & Mine-Like Objects Kevin Williams, Steven Kargl, Aubrey España (PDF 3 MB)

Acoustic Detection of Unexploded Ordnance Aubrey España's presentation at the 31 Oct 2011 Acoustical Society of America's Webcast on Discoveries in Acoustics (Quicktime Movie, 64 MB)

Acoustic Intensity Properties in an Ocean Waveguide David Dall-Osto, Peter H. Dahl (PPT 2 MB)

Modeling a Spiral Wave Front Source in an Ocean Environment Brian T. Hefner, Benjamin R. Dzikowicz (PDF 15.6 MB)

Pressure-particle Velocity Coherence David Dall-Osto, Peter H. Dahl (PPT 3 MB)

Physics-Based Inversion of High-Frequency Multibeam Sonar Data Darrell Jackson and Brian T. Hefner (PDF 250 Kb)

In the News

Chasing Noise

Washington Sea Grant Sea Star

25 Jul 2016

Acoustical engineers show how seabed terrain affects sound waves — and how marine construction can cost less and still protect marine mammals.

The whale wiretap: Oceanographer's underwater microphones eavesdrop on the secret lives of whales

KPLU Radio,

9 Apr 2016

Deep down on the sea floor off the coast of Alaska, about a dozen underwater microphones sit. Kate Stafford listens back to these recordings with the help of high-tech software to learn more about whales. Sound Effect's Gabriel Spitzer talked with her about what she's learned and what it's like to eavesdrop on the ocean.

Some whales like global warming just fine

National Geographic,

5 Apr 2016

Humpbacks and bowheads are benefiting — for now, at least — from the retreat of polar sea ice: It's making it easier for them to find food.

Recent Papers

Stafford, K.M., M.C. Ferguson, D.D.W.Hauser, S.R. Okkonen, C.L. Berchok, J.J. Citat, J.T. Clarke, E.C. Garland, J. Jones, and R.S. Suydam, "Beluga whales in the western Beaufort Sea: Current state of knowledge on timing, distribution, habitat use and environmental drivers," Deep Sea Res. II, EOR, doi:10.1016/j.dsr2.2016.11.017, 2016.

2 Dec 2016, Link

Lin, P., R.S. Pickart, K.M. Stafford, G.W.K. Moore, D.J. Torres, F. Bahr, and J. Hu, "Seasonal variation of the Beaufort shelfbreak jet and its relationship to Arctic cetacean occurrence," J. Geophys. Res., EOR, doi:10.1002/2016JC011890, 2016.

16 Nov 2016, Link

Stafford, K.M., J.J. Citta, S.R. Okkonen, and R.S. Suydam, "Wind-dependent beluga whale dive behavior in Barrow Canyon, Alaska," Deep Sea Res. I, EOR, doi:10.1016/j.dsr.2016.10.006, 2016.

18 Oct 2016, Link

Educational Opportunities

Graduate and undergraduate students can work under the tutelage of the Acoustics Department investigators through their respective home UW academic colleges, including oceanography, engineering, and earth and space sciences.  More >>

Dr. Peter Dahl, for example, teaches Applied Acoustics (Mechanical Engineering 525), which introduces acoustics through its various applications and sub-fields, such as underwater sound (inlcuding sonar), medical ultrasound, and noise control and vibration.