There are many studies that say that the dolphins have a very difficult and complex communication system. The researches call it “language”.
The language’s dolphin is formed by “chasquidos” (similar to growl) and whistles to transmit and to receive information. The growls form a system similar to radar or boat sonar. The whistles that the dolphins emit are unintelligible for the man because their tones and their frequencies are higher than those of the human languages.
The dolphins are animal that can help to persons with different incapacities (physical or emotional disorders). The dolphins emit ultrasonic waves of different types that circulate around the body of the treated person and which produce an activation of the nervous system. The dolphin-therapy is a method to treat autism, syndrome of down, cerebral paralysis… among others.
I didn’t know anything about the dolphins trained by the US military but I have read in internet that it is true. There are dolphins that they are trained to transport, detect an put mines. I have found an article where says that four dolphins were carried to the south coast of the Irak to detect mines placed in the port. The military strategy failed when a flock of “Arabs Dolphins” appeared. The Americans Dolphins decided that it was better play with them that make war.