So what if it was now known that they could not only produce sound, but utilize that ability to have x-ray vision as well? There is a small sac of fatty tissue that is found below the dolphins' jaws that collects the sound waves that bounce off objects. In response, it sends them through the dolphin's inner ear to be heard at a high frequency to detect. This causes a snow ball effect that it leads to being passed on to the brain through the dolphin's neurons. the signal that gets transmitted gets translated to what is know as a "acoustical holographic image." Researchers have discovered that this is what allows them to perceive the image of exactly what is in front of them. When used in short distances across the ocean/water, it is effective.
This leads to the remarkable ability that with high frequencies and at short wavelengths, dolphins can see through other animals. It travels through the soft bodies of other fish, and the frequency waves bounce off of its hard surfaces like its skeletal structure. So like seeing the bones of the animal in front of them allow the dolphins to take a mental picture with increasing clicks of frequencies that it produces and receives. Specifically Bottle-nose dolphins are the species that use this characteristic most, based on their behaviors. For example, when a dolphin clicks along the seabed, to find hidden fish that hide up to three feet below the soft sediment. Not only can they find their prey using this sense, dolphins use a type of cross-model matching. Researchers have tested this theory with humans with the example that an object that you feel without looking at will be engraved as a mental thought in one's mind.
What I found interesting was that with this matching, dolphins can cross reference objects and so seeing a skeletal structure is incredibly advantageous. The concept is the same for dolphins, except at a higher level in which they can use the frequencies to remember the image. I never in a million years would have thought that dolphins could do something this advantageous. By taking a mental picture of objects through the use of sound is something that I find really interesting.
Sweeting, Kelly M. (2014, March). Dolphin Communication Project
Handley, Andrew. (2013, Oct. 28). 10 Interesting Facts About Marine Life. Listverse.