Your child’s sense of hearing is fully developed from birth. Early on, she’ll show a preference for human voices, especially higher-pitched ones, over all other sounds. So talk to her! Consult your pediatrician if she isn’t startled by loud noises or doesn’t seem to respond to your voice at all by 2 months. Most states have hearing screening requirements for newborns; be sure to follow up on any recommendations related to your baby’s results.