Measurement and Analysis of Echolocation Clicks of Free-Swimming Dolphins (T. truncatus) in a Tank with Echo-Reducing Wood Lining.

Abstract

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)

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Document Details

Document Type
Technical Report
Publication Date
May 21, 1981
Accession Number
ADA099211

Entities

People

  • L. Dwight Luker
  • Lynn B. Poche Jr.
  • Peter H. Rogers

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Reflection
  • Ambient Noise
  • Bandwidth
  • Concrete
  • Construction
  • Detection
  • Frequency
  • Frequency Response
  • Hydrostatic Pressure
  • Materials
  • Measurement
  • Noise
  • Orientation (Direction)
  • Recording Systems
  • Tape Recorders
  • Transmission Loss
  • Underwater Sound

Readers

  • Fluid Dynamics.
  • Marine Mammal Biology
  • Radar Systems Engineering.