The localized concentration of energy during a single bubble collapse is manifested in two forms, which are the emission of an acoustic pulse, and the emission of a light pulse. Through precise control of experimental parameters, one can levitate a single bubble in a standing wave field and measure the magnitude of the acoustic and light pulses resulting from the violent collapse of the cavity. The information acquired from such measurements provides better understanding of the mechanisms that are responsible for the emissions, which may lead to the practical application of controlled bubble implosions. An experimental apparatus was developed to measure the acoustic and light emissions from a single, stable sonoluminescing bubble. Two surfactant additives were studied to determine the effects on the bubble emissions. Triton X-100, which has previously been shown to provide free interfacial motion, reduced the magnitude of both the acoustic and light pulses from the bubble. The protein bovine serum albumin (BSA) which has been shown to hinder interfacial motion, allowed the bubble to be driven to higher acoustic pressures, and resulted in an increase in the magnitude of the light pulses from the bubble. Images of the sonoluminescing bubble indicate that the collapse remains spherical in the cases presented, and that bubble translation can be correlated with weak acoustic and light emissions.

The localization concentration of energy during a single bubble collapse is manifested in two forms, which are the emission of an acoustic pulse, and the emission of a light pulse. Through the precise control of experimental parameters, one can levitate a single bubble in a standing wave field and measure the magnitude of the acoustic and light pulses resulting from the violent collapse of the cavity. An experimental apparatus was developed to measure the acoustic and light emissions from a single, stable sonoluminescing bubble. Two surfactant additives were studied to determine the effects on the bubble emissions. Triton X-100, which has previously been shown to provide free interfacial motion, reduced the magnitude of both the acoustic and light pulses from the bubble. The protein bovine serum albumin (BSA), which has been shown to hinder interfacial motion, allowed the bubble to be driven to higher acoustic pressures and resulted in an increase in the magnitude of the light pulses from the bubble. Images of the sonoluminescing bubble indicate that the collapse remains spherical in the cases presented, and that bubble translation can be correlated with weak acoustic and light emissions.

Recent mass strandings of beaked whales (Ziphiidae, Cetacea) coinciding with the use of midfrequency range (1–10 kHz) active sonar have caused speculation about the potentially adverse effects of these sound sources. Particular questions of the research and regulatory communities concern whether beaked whale sensitivity to midfrequency sound exposure is influenced by oceanographic characteristics present at the time of the mass stranding events. This study investigated the interaction between beaked whale habitat characteristics and the nature of a midfrequency signal by analyzing the oceanographic factors affecting underwater acoustic propagation. Three types of model sites were selected from five specific geographical locations where beaked whales have been regularly recorded or where a mass stranding event has been reported. A ray-trace acoustic propagation model was used to generate transmission loss for a 3-kHz signal over a representative 60-km transect at each locality. Model outputs visually demonstrated how the combination of site/event-specific oceanographic characteristics affects the sound propagation of a moving source. A parametric sensitivity comparison and statistical analysis were conducted to identify influential factors between environmental parameters, source depth, and the resulting transmission loss. Major findings of this study as well as future research direction are discussed. [Research supported by NAVSEA.]

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