There are many factors that facilitated the rise to sapience of the human race. One of them was our superb air flow control over our vocal chords. It is an ability in which we are unique among primates and was an important preadaption that made fluent speech possible. I find it interest then, that sperm whales were recently found to be unique among cetaceans in this very same trait. Today, it is assumed that the discrete way each sperm whale coda breaks down into scores of subcoda under Duda-Hart analysis is due to an as yet unknown factor, not because they have a true language. This evidence hints otherwise.
Once more, an unexpected finding that groups sperm whales apart from every other cetaceans, and alongside humans. For some of the others factors that are common to sperm whale and humans to the exclusion of all other animals, see my summary of evidence here.