A developing fetus begins to hear at about 30 weeks, and now researchers have learned that as the delivery date approaches, a fetus begins to distinguish its mother's voice from that of a stranger.
Sixty Chinese women were divided into two groups, and fetal heart rates were measured before, during and after a pre-recorded two-minute poem was played through a speaker held above the mother's abdomen.
The heart rate increased about five beats a minute in 21 of the 30 fetuses who heard recordings of their mothers' voices. Heart rates slowed about four beats a minute in 21 of the 30 fetuses who heard a recording of a stranger's voice.
"There's some sort of representation that the fetus is matching with the sound," says lead author Barbara S. Kisilevsky, a professor of nursing and obstetrics and gynecology at Queen's University in Kingston, Canada.
This study was published in the May issue of Psychological Science.
Dianne Partie Lange