Basic Hearing and Echolocation Mechanisms of Marine Mammals: Measured Auditory Evoked Potential and Behavioral Experiments FY 2008

摘要

Examine the control of hearing during echolocation. Broaden the baseline of hearing measures of marine mammals by increasing the number of animals and species measured. The effects of sound on wild populations of animals can best be determined if baseline hearing measures are known. Improve the measurement of marine mammal hearing by developing and refining hearing procedures particularly those that will rapidly measure the hearing of stranded and temporarily caught animals. Comparatively examine the basic hearing mechanisms of marine mammal species. Compare the auditory evoked potential and behavior psychophysical methods for examining hearing in odontocetes. Examine the effects of loud sound on dolphin hearing and temporary threshold shifts - particularly those frequencies used in the midfrequency sonars like the 53-C. Develop an understanding of the basic processes of odontocete echolocation. Develop and refine the measurement of hearing during echolocation particularly the hearing of the outgoing signals and the echoes from nearby and distant targets. Examine automatic gain control mechanisms in odontocete echolocation. Develop an understanding of the basic processes used by odontocetes to actively discriminate fine differences in echolocation targets and to model those processes for use in the development of improved sonars.