I am amazed by the new 4D ultrasounds that have become popular with mothers in the last few years. These incredibly detailed images allow anticipation-filled parents-to-be view a 3D image of their growing baby. They can then see its tiny movements so clearly, it is as if they are seeing their already-born child. I had the opportunity to see this firsthand when a dear friend invited me to her ultrasound a few weeks ago. I thought this a little strange until we entered the room and saw it was nothing like the clinical environment I was expecting. Instead, there was a seating area set up with comfy couches and the rest of the room looked like an extremely feminine bedroom. As the technician glided the wand across my friend’s belly and the images of the baby came onto the screen, we were all completely rapt. A few moments into the ultrasound my friend’s husband leaned close to her belly and said the name of their future baby. I was stunned to see the tiny 3D face turn toward him. They were delighted as well, even more so when the technician said it was not a fluke and that the baby actually recognized his voice. She even announced the baby would be able to identify his father after birth. Could this possibly be true? Can a newborn really differentiate his parents’ voices from others?

Studies have indicated newborns have the ability to differentiate the sound of his parents’ voices from those of other adults from the time of birth. Experiments involved playing recordings of parental voices and those of strangers to babies soon after birth. All newborns involved in the study showed changes in their heart rate and respiration indicating consistent recognition when their parents’ voices were played. Such changes were not noted in the babies when they heard voices of adult strangers. These recordings lasted for a full four minutes, during which the responses remained consistent. Many researchers believe newborns are more likely to respond strongly to their father’s voice as it is deeper, therefore more easily heard when in utero. Others note the babies hear their mother’s voice all the time, and are, therefore, more likely to respond to her voice. Studies have shown there is a consistent ability for newborns to recognize both parents’ voices, but some show preference for one or the other which may relate to simply preferences in tone and depth.

Source: Kisilevsky, Barbara. Effects of Experience on Fetal Voice Recognition, Psychological Science, May 2003, Volume 14, Issue 3, pp 220-224.