Have you ever wondered as to when does a foetus actually start hearing? We all hear of how babies respond to sounds from within their mother’s womb, from voices to music. Do they really hear, and if yes, when does it all begin?
The development of a foetus occurs in stages, as is the tradition of life on our little blue planet. The baby’s many different tissues and organs are organised in phases as it grows inside its mother. Research says that a baby can hear sounds as from around week 16 of pregnancy as its inner ear structures (or most of them, anyway) will have formed by then. The important parts – like the cochlea, eardrum, and ossicles – are completely fashioned in another 8 weeks; by 24 weeks, babies can, thus, hear sounds coming their mother, from her heartbeat to her breathing to her talking.
Previous studies have shown that babies might even be able to recognise their mother’s voice from the womb. Another study mentions that consistent responses to sound were seen in babies as from 28 weeks.
Now, if babies can hear, can loud sounds be disturbing to them, and are they vulnerable to too much noise? Given the potential risks, experts have advised mothers not to be exposed to extremely loud noises (like gunfire or loud music) to avoid harm to babies. It is also argued that persistent loud noise might adversely affect babies’ hearing structures, says a paper published in Pediatrics.
In an article published on J Obstet Gynecol Neonatal Nurs, which mentions the formulation of recommendations pertaining to safe exposure to sound during early development of both foetuses and preterm infants, it is said that “intense and sustained sound” can have serious effects on the development of the vascular system and brain of the foetus.
To what extent can babies be harmed by loud sounds? “Foetuses can hear ultrasound and the sound is as loud as a subway train entering a station“, says another research, but this information was only mentioned in a study that has not been peer-reviewed, and another study challenges this point of view, arguing that no evidence of any harm to babies relating to this has been found.