"Simply talking with an infant is a wonderful way to build attention, working memory, and self-control." Center on the Developing Child HARVARD UNIVERSITY
Babies love "conversations" where there is give and take. Their response IS with gurgling and babbling. Talking with your baby will help them talk, trust and learn. Somewhere around 4 to 6 months of age many babies will start to make sounds like "mmm" or "bbb" to interact with you.
The first language skill to develop is understanding what is heard. By around 6 months of age, most babies recognize the basic sounds of their parent's language.
Babies have the need for social interactions and lots of talk from loving adults also builds healthy relationships and social skills: building trust, dealing with emotional and physical needs, and interacting with others in positive ways. Many babies will calm down or smile when spoken to like the baby in the photo above.
By around 8 months of age some babies will try and imitate sounds that they hear. Keep in mind that all children vary in their development of language skills.
TALKING AND DEVELOPMENT: Research has shown that children from talkative families may have heard 30 million more words by age 3 than children from less-talkative families and that the more words the children had heard by age 3, the better they did on tests of cognitive development.
Having a talk in any language is a wonderful thing as bilingual children have been found to have better executive functioning skills than children who speak one language.
Tips on Learning to Talk from birth at Zero to Three