Most of us have heard the Indian mythological story of Abhimanyu, from Mahabharata, where he learned war strategies by listening to his father when he was still in his mother’s womb. However, in recent times, many studies have positively indicated that on listening to their mother’s voice and heartbeat, babies get a brain boost in the womb.
Prematurely born infants are more than twice likely to have difficulty in hearing and processing words, as the regions of the brain that are related to processing sound are not fully developed at the time of birth. Now, a new study reveals that the recordings of mother’s voice and heartbeat to recreate a womb like environment can correct these defects. A fetus starts to hear at about 24 weeks of gestation. A fetus, once the auditory cortex (sound processing region of the brain) starts functioning, hears mostly low frequency sound, like the mother’s heartbeat and her voice. This phenomenon is thought to be partly responsible for the strong bond that a baby forms with the mother. Researchers believe that this introduction to sound may be a key part in the early acquisition of language that gets disrupted if the baby is born prematurely.
Recently, researchers at the Harvard University played recordings of their mother’s voices (singing and reading) and heartbeat to twenty premature babies in incubators. These sounds were altered to sound like the noises experienced in the womb. The auditory cortexes of infants who were exposed to these sounds grew larger than twenty other infants who were exposed to background noises. It suggests that in the care of premature babies, mothers could play a great role.
Dr Amir Lahav, who conducted this study, says that replicating the sounds experienced by the child in the womb appears to be more beneficial than the shrill noises experienced in the hospital.
For this study, the scientists recorded the sound of the heartbeat of mothers using microphones and stethoscope. They also recorded them singing Twinkle Twinkle Little Star and Goodnight Moon. They did this for mothers of forty premature babies. Later on, they played the sounds to only half of the babies, for 3 hours a day, 45 minutes at a time. 30 days later, upon measuring the growth of the brain using ultrasound scans, it was found that those who were played the sound of their mothers had a far thicker auditory cortex than those who were not. The scientists say that although it may improve the development of premature babies, the impact it will have on how they would fare later in life is still not known.
Dr Lahav, along with his colleagues, plans to follow the babies to see the development of their speech and hearing.
The authors of the study that was published in ‘Proceedings of the National Academy of Science’ conclude it by the statement, “Our results demonstrate that despite the immaturity of the auditory pathways, the [auditory cortex] is more adaptive to maternal sounds than environmental noise. Further studies are needed to better understand the neural processes underlying this early brain plasticity and its functional implications for future hearing and language development.”