Motherese

In a review of Sarah Blaffer Hrdy's Mothers and Others: The Evolutionary Origins of Mutual Understanding, Melvin Konner stumbles upon this gem:

Of all the calls, hoots, and screeches issued by our chimpanzee relatives, the only ones that sound a little like human speech are the coos exchanged in quiet moods by mothers with their young; the first language may have been “motherese.”