Customer Support
+34 972 661 661
Price (inc. VAT)
€149.00
€199.00
Offer
-25%
Price (inc. VAT)
€69.95
€75.00
Offer
-7%
Price (inc. VAT)
€29.95
€62.00
Offer
-52%
Price (inc. VAT)
€89.00
€249.00
Offer
-64%
Price (inc. VAT)
€125.00
€195.00
Offer
-36%
Price (inc. VAT)
€59.00
€101.00
Offer
-42%
Price (inc. VAT)
€368.00
€498.00
Offer
-26%
Price (inc. VAT)
€25.00
€57.00
Offer
-56%
Price (inc. VAT)
€3,925.00
€5,375.00
Offer
-27%

Underwater Acoustics

The acoustic underwater differs in many ways from the airborne sound we are used to. The sound velocity underwater is varying between 1450 and 1550 m/sec depending on temperature, salinity and depth. This results in 4 to 4.5 times bigger wave lengths as well as in a special sound phenomenon called the SOFAR, also known as Underwater Sound Channel. Horizontally sound can travel over huge distances whereas vertical propagation is strongly attenuated.

Here are some useful advices:
  • Sound Channels (USC, SSC,…) can be avoided by knowing their local depth
  • To avoid the noise from braking waves on the boat hull, take long enough cables to go down deep enough or prepare to record in greater distance to the vessel.
  • Take time for detailed micro-phasing when recording in pools or artificial environments as bigger wave lengths underwater lead to greater distances between sound maxima and minima.
  • Never forget how far low frequencies can spread underwater. Therefore, avoid touristic areas for documentary shots.
  • Water owns a reflection factor close to 1, thus, airborne sound virtually can’t couple directly into water. This phenomenon can be used, if barriers reach close to the water surface (reefs, wave-breakers, e.g.) you can use them as acoustic barriers, independent of the current depth. This way you may find acoustic cover in a pool with 1m depth behind an 80 cm wooden block, even though the wavelength underwater wouldn’t suggest this.
Do you have any doubts?