Ann E. Bowles
Hubbs--Sea World Res. Inst., 2595 South Shores Rd., San Diego, CA 92109
Models developed to describe and mitigate damage to human hearing after sonic-boom exposure can be applied to a wide range of species. If humans and laboratory animals are poor models for a species of concern, or if intense focused sonic booms are anticipated, experimental assessments will be needed. Although attenuation across interfaces (air--water and air--soil) will protect many aquatic and fossorial species, attenuation may not protect individuals near the interface if boundary phenomena like evanescent energy are found to be important. Panic reactions are a likelier hazard for animals, at least in air. Damage in panics is predicted best by species-typical avoidance behaviors (e.g., panic flight), sound exposure level (after appropriate weighting), and previous experience with impulsive man-made noise. Dose-effect models have not been developed because controlled experimental studies with booms at levels up to 150 dB (peak flat SPL) have failed to elicit panics. However, widespread concern continues because there are circumstantial accounts of catastrophic damages, notably the ``Sooty Tern Incident.'' Controlled studies of habituation using initially naive animals are needed to develop dose-effect models for damaging responses. Effects of impulse-induced frights on (1) gametogenesis, conception, and early embryonic development, (2) parental care, (3) activity, and (4) habitat use should be investigated as well.