Is it true about the noises heard under water?

Question

Is it true about the noises heard under water?

Answer 1

No

Answer 2

Sound is the only form of energy that will propagate reliably underwater, and for this reason it is used by aquatic animals for imaging, navigation and communication. Man also uses sound for the same reasons underwater, and additionally generates noise as a byproduct of offshore activity.

When sound is generated underwater, it will have a relatively high level near the source. The level of sound will be attenuated as the sound propagates away from the source, and at some distance it will decay to the level of the background noise in the ocean. The distance within which this will occur, and hence the range within which environmental effects could occur, will depend both on the level of sound generated by the source and on the rate at which the sound decays.

Man-Made Noise Underwater

   1.  Shipping noise

   2. Pile driving and construction noise

   3. Sonar and related research equipment

   4. Underwater explosives and blasting

   5. Offshore oil exploration and production

With decibles n source of noise description... ( chart is given)

http://www.underwaternoise.org.uk/noise_...

Impacts from noise on marine life have been found

http://www.terranature.org/oceanNoise_We...