Final answer:
Infant-directed speech, or baby talk, positively impacts infants by enhancing their phonological development, helping them to better discriminate sounds and potentially learn vocabulary faster.
Step-by-step explanation:
Research by Dr. Laurel Trainor at McMaster University and others in the field of language development suggests that infant-directed speech, commonly known as baby talk, has a positive impact on language development. Among the various benefits, it particularly enhances phonological development in infants. This form of communication often involves a high-pitched, sing-song voice that infants are thought to find more engaging and easier to attend to, which can lead to better phonetic discrimination and more rapid vocabulary acquisition.