Underwater Acoustics - Measurements


Sound in water is measured using a hydrophone, which is the underwater equivalent of a microphone. A hydrophone measures pressure fluctuations, and these are usually converted to sound pressure level (SPL), which is a logarithmic measure of the mean square acoustic pressure.

Measurements are usually reported in one of three forms :-

  • RMS acoustic pressure in micropascals (or dB re 1 μPa)
  • RMS acoustic pressure in a specified bandwidth, usually octaves or thirds of octave (dB re 1 μPa)
  • spectral density (mean square pressure per unit bandwidth) in micropascals per hertz (dB re 1 μPa²/Hz)

Read more about this topic:  Underwater Acoustics

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