The purpose of this RCT is to learn more about how sounds that we experience in the womb can affect early development in premature infants. The investigators are specifically interested determining whether and what types of maternal auditory stimulation can influence physical growth, brain maturation, respiratory stability (including heart rate, respiratory rate and oxygen saturation levels) as well as early vocalization prior to 40 weeks gestation. The investigators hypothesize that daily exposure to biological maternal sounds, such as mother's voice and heartbeat, will improve both short-term and long-term developmental outcomes in premature infants and will increase their potential to grow into healthy children.