Biological Choruses in the Eastern Indian Ocean.

Abstract

This report is a summary of observations of biological choruses in the eastern Indian Ocean. The data were collected from underwater noise recordings made in the course of sonar performance trials at four sites north-west of Australia, located in intermediate and deep water. Measurements are made for frequencies between 20 Hz and 800 Hz. Chorus noise at 500 Hz consisting of continual drumming sounds, was evident for 10 hours in the evening, with the peak noise level occurring soon after sunset. The noise spectrum level at this peak frequency rose to 72 dB re 1 micro Pa2/Hz, approximately 10 dB above the background noise level. Typical spectra and time waveforms for individual noise bursts are presented. The source of the noise is believed to be fish of the family Sciaenidae, commonly known as croakers.

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1983
Accession Number
ADA143624

Entities

People

  • A. S. Burgess
  • D. J. Kewley
  • L. J. Kelly

Tags

DTIC Thesaurus Topics

  • Australia
  • Background Noise
  • Deep Water
  • Fish
  • Frequency
  • Frequency Shift
  • Indian Ocean
  • Measurement
  • Noise
  • Observation
  • Oceans
  • Spectra
  • Water

Readers

  • Acoustics.
  • Military History of the United States in the 20th Century.
  • Oceanography.