Laurel J Trainor and Christine A Zacharias (1998)
Infants prefer higher-pitched singing
Infant Behavior and Development, 21(4):799–805.
Female singers were recorded singing a song in a high and/or a low range. Infants preferred to listen to the higher-pitched versions, suggesting that infants' preference for infant-directed singing and speech is mediated in part by a preference for higher pitch.