Baby talk. It is how many adults speak to babies: slowly, using shorter sentences, talking at a higher pitch, and putting more emphasis on certain vowels. Examples include, “Where are your shoooes?” And, “Oh, this tastes gooood.” New research from Princeton University in New Jersey found something else special about how adults -- in this case mothers -- speak to their very young children. “We found for the first time that mothers shift their vocal timbre,” said Elise Piazza, a postdoctoral researcher at Princeton University’s Neuroscience Institute. Timbre is what makes a sound appear different than words or music with the same pitch and loudness.