Acoustical Oceanography
“Broadband backscattering from scyphozoan jellyfish,” by Rachel E. Kahn, Andone C. Lavery, and Annette F. Govindarajan.

TC Chair David Barclay says, “Not all Acoustical Oceanography must take place in the ocean – sometimes the ocean is brought into the lab. This paper describes careful tank measurements of the acoustic backscatter from a scyphomedusa (a common jelly fish found in Chesapeake Bay) and the theory to match.  This work can be used to better estimate and understand the growing abundance and spatial distribution of jellyfish and other gelatinous zooplankton.”

Animal Bioacoustics
“Sound sensitivity of the giant scallop (Placopecten magelanicus) is life stage, intensity, and frequency dependent,” by Youenn Jézéquel, Seth Cones and T. Aran Mooney.

TC Chair Laura Kloepper says, “Understanding the effect of anthropogenic sound on living organisms is crucial for species management and conservation, but we still lack fundamental information on sound sensitivity for many species, most notably invertebrates. This study investigates the effect of life stage on hearing sensitivities in the giant scallop, and results indicate differences in hearing sensitivity between juveniles and subadults. The results conveyed in this paper motivate the need for future studies on the auditory perception in invertebrates and a consideration of how hearing may change across life stage.”

Computational Acoustics
“Anisotropic minimum dissipation subgrid-scale model in hybrid aeroacoustic simulations of human phonation,” by Martin Lasota, Petr Šidlof, Paul Maurerlehner, Manfred Kaltenbacher, and Stefan Schoder.

TC Chair Keith Wilson says, “Production of vowel sounds by the larynx involves extremely complex turbulent flow through the vocal folds. The authors couple state-of-the-art turbulence simulations to acoustic finite-element methods to describe this process in three dimensions. The subgrid-scale model (that is, the model for the turbulent flow variations that are unresolved by the simulation) is found to be particularly important. A new approach, called the anisotropic minimum dissipation (AMD) model, is found to provide the most realistic sound production.”

Engineering Acoustics
“A liquid column resonance transducer driven by Class IV flextensional transducer,” by Shichang Li, Yu Lan, and Lianjin Hong.

TC Chair Michael Haberman says, “The generation of low frequency sound underwater is complicated by the fact that commonly used transducers, like flextensional transducers, have high mechanical compliance and are therefore not mechanically robust to high ambient pressures. This work overcomes this problem by integrating a liquid column resonator, i.e. an organ pipe, with an optimized Class IV flextensional transducer as the driving source to create a broadband and pressure tolerate device with high transmit levels. The authors present numerical models for analysis and design and then fabricated and test the response of prototype device, which is an good agreement with model predictions.”