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dc.contributor.advisorMoss, Cynthia F.en_US
dc.contributor.authorAytekin, Muraten_US
dc.date.accessioned2007-06-22T05:35:36Z
dc.date.available2007-06-22T05:35:36Z
dc.date.issued2007-05-14
dc.identifier.urihttp://hdl.handle.net/1903/6854
dc.description.abstractEcholocating bats emit ultrasonic vocalizations and listen to echoes reflected back from objects in the path of the sound beam to build a spatial representation of their surroundings. Important to understanding the representation of space through echolocation are detailed studies of the cues used for localization, the sonar emission patterns and how this information is assembled. This thesis includes three studies, one on the directional properties of the sonar receiver, one on the directional properties of the sonar transmitter, and a model that demonstrates the role of action in building a representation of auditory space. The general importance of this work to a broader understanding of spatial localization is discussed. Investigations of the directional properties of the sonar receiver reveal that interaural level difference and monaural spectral notch cues are both dependent on sound source azimuth and elevation. This redundancy allows flexibility that an echolocating bat may need when coping with complex computational demands for sound localization. Using a novel method to measure bat sonar emission patterns from freely behaving bats, I show that the sonar beam shape varies between vocalizations. Consequently, the auditory system of a bat may need to adapt its computations to accurately localize objects using changing acoustic inputs. Extra-auditory signals that carry information about pinna position and beam shape are required for auditory localization of sound sources. The auditory system must learn associations between extra-auditory signals and acoustic spatial cues. Furthermore, the auditory system must adapt to changes in acoustic input that occur with changes in pinna position and vocalization parameters. These demands on the nervous system suggest that sound localization is achieved through the interaction of behavioral control and acoustic inputs. A sensorimotor model demonstrates how an organism can learn space through auditory-motor contingencies. The model also reveals how different aspects of sound localization, such as experience-dependent acquisition, adaptation, and extra-auditory influences, can be brought together under a comprehensive framework. This thesis presents a foundation for understanding the representation of auditory space that builds upon acoustic cues, motor control, and learning dynamic associations between action and auditory inputs.en_US
dc.format.extent4625237 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.titleSound Localization by Echolocating Batsen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentPsychologyen_US
dc.subject.pqcontrolledPsychology, Experimentalen_US
dc.subject.pqcontrolledPhysics, Acousticsen_US
dc.subject.pquncontrolledecholocationen_US
dc.subject.pquncontrolledbatsen_US
dc.subject.pquncontrolledsonaren_US
dc.subject.pquncontrolledsensorimotoren_US
dc.subject.pquncontrolledsound localizationen_US
dc.subject.pquncontrolledspatial perceptionen_US


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