Chapter 2 Prenatal Experience with the Maternal Voice
Research studies over the past 40 years have established that the maternal voice is a prominent feature of the prenatal environment, that the fetus responds to it, and that prenatal learning carries over into early postnatal life. The primary aim of the chapter is to describe what is known through research about prenatal exposure to the mother's voice, especially through audition. A second aim is to present a consideration of nonauditory experience such as the vestibular and, possibly, cutaneous sensations that are uniquely linked to auditory stimulation by the maternal voice. A third aim is to raise a question about the necessity of prenatal experience with the acoustic aspects of the maternal voice, given emerging data from deaf infants who receive cochlear implants many months after birth. The chapter concludes by considering implications for the care of hospitalized preterm infants who experience atypical experience with the mother's voice and other sounds. Chapter conclusions are (1) fetal auditory experience with the mother's voice begins around 24 weeks after conception, (2) the maternal voice is potentially a rich source of multimodal stimulation and information, and (3) for favorable postnatal development, the role that is played by very early exposure to the maternal voice is not yet understood. When Elizabeth heard Mary's greeting, the baby leaped in her womb, and Elizabeth was filled with the Holy Spirit. (Luke 1:41, Bible New International Version) The scientific method has confirmed what has been passed down for at least two millennia. Research results converge to show that the fetus begins reacting to maternal and other acoustic signals before birth. Resourceful twentieth century investigators devised procedures to record what sounds could be generated within the womb or be transmitted from the outside. In addition, they learned how to measure both fetal and neonatal responses to particular sounds. Audio recordings in the womb show that a strong maternal voice signal is available to the fetus. Fetal cardiac and motor activity show a reaction to the mother's voice, and there is a good reason to believe that the sound of her voice is retained across the transition into postnatal life. C. Moon Pacific Lutheran University, Department of Psychology, Tacoma, WA, USA e mail: mooncm@plu.edu