Seals have the ability to make sounds like humans. Amanda Stansbury, one of the leading scientists of the case investigating this mammalian phenomenon, gave her insight into the study and its effects on and implications of human speech.
Further Reading
Formant Modification through Vocal Production Learning in Gray Seals (Current Biology)
Videos of the seals from the study singing (Associated Press)
Listen to Hoover, the talking seal from Boston (New England Aquarium)