This research does not diminish the importance of the speech that babies hear from others. It suggests that they are actively engaged in their own development.

Fagan said, "This research does not diminish the importance of the speech that babies hear from others. We know they need to learn from others, but it raises our awareness that infants are not just passive recipients of what others say to them. They are actively engaged in their own developmental process."
For the study, researchers studied the babbles of 27 hearing infants and 16 infants with profound hearing loss before and after they received cochlear implants. Cochlear implants are small electronic devices embedded into the bone behind the ear that replace some functions of the damaged inner ear. Before receiving cochlear implants, babies with profound hearing loss rarely produced repetitive vocalizations, such as 'ba-ba' or 'da-da.'
Fagan said, "Within a few months of receiving cochlear implants, the number of babies who produced repetitive vocalizations increased, the number of vocalizations that contained repetitive syllables increased, and the number of actual repetitions in the string, such as 'ba-ba-ba-ba-ba,' increased. The research tells us that infants are motivated by hearing the sounds they produce, so these sounds are functional in some way."
Source-IANS