Measurement and Analysis of Echolocation Clicks of Free-Swimming Dolphins (T. truncatus) in a Tank with Echo-Reducing Wood Lining.
NAVAL RESEARCH LAB WASHINGTON DC
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Echolocation signals of two dolphins were measured in an experiment, and aspects of the measurement methodology are discussed. An anechoic wood tank lining was developed that gave an echo reduction of 15 to 25 dB and a transmission loss of 10 to 35 dB over the range of 10 to 150 kHz. The lining was constructed in modular panels and could be removed readily should the need arise. Echolocation click energy peaks in the 20- to 30-kHz and 100- to 130-kHz ranges were observed, but none in the often-reported range of 30 to 60 kHz. Peak-to-peak source levels for the clicks averaged about 165 dB re 1 micron Pa. Clicks that had both low- and high-frequency energy peaks showed a fixed time relationship between these parts. Author
- Biological Oceanography
- Acoustic Detection and Detectors