Do dolphins talk? Maybe. They at least communicate with each other.

In 1962 Dr. Dreher and Dr. Evans were aboard the research vessel Sea Quest, 300 miles south of San Diego, studying gray whales. They had strung a number of vertical aluminum poles and microphones inside Scammon's Lagoon, erecting a type of barrier. A short time later five Pacific Bottle-nosed dolphins were spotted about 500 yards from the barrier. After a few minutes of what was labeled conversation, a scout was sent from the group. Microphones picked up his sonar soundings as he closely surveyed the poles. When he returned to the pod an explosion of whistles, chirps and Bronx cheer-like noises were recorded via microphones. After several minutes of conversation the dolphins proceeded through the barrier and into the bay.