Do Sperm Whales Have Names? Possibly...
The research is very preliminary and up to this point is based on only three whales, but researchers Luke Rendell, Jonathan Gordon, Hal Whitehead, Shane Gero, and others who have been working with whale auditory research believe that the data is "very suggestive" that this type of communication is taking place during whale click sequence (or "coda") communications.
In recent work with these sperm whales, the group found a unique 5R coda identifier (series of 5 clicks) that all sperm whales broadcast world-wide -- normally at the beginning of a click sequence. When analyzed with a particular sound analysis technique, however, a statistically significant variance in click timing was observed for each individual whale for this 5R coda.
According to the Wired article: "Rendell stressed that much more research is needed to be sure of 5R’s function.'We could have just observed a freak occurrence,' he said. Future research will involve more recordings. 'This is just the first glimpse of what might be going on.'"