The development of the sense of hearing in the fetus has been the subject of study and controversy for many years.
Currently, evidence has shown that the baby in the womb is capable of hearing sounds in the last trimester of pregnancy.
However, it is known that the fetus responds to sound from week 16 although the ear structures are not fully mature. The researchers say that the baby then perceives the sounds through some other alternative system. This alternative system to the ear would be the skin. This would act as a great receptor organ for vibratory information, transmitting it through the amniotic fluid in which the fetus is submerged.
The structural parts of the outer ear and the middle ear develop over the first 20 weeks.
And it is from the 25th week of gestation when the hearing organ is already functional. According to the American Academy of Pediatrics, from this moment on, the fetus is able to perceive, through the amniotic fluid that surrounds it, the sounds inside the mother's body: the heartbeat, blood circulation, breathing, the activity of the digestive system ... The fetus also perceives the mother's voice It is transmitted through the spinal column and reaches the sacrum.
It has been proven that the mother's voice exerts a comforting effect on the fetus, but not because of the meaning of the words, since the fetus cannot understand the meaning of verbal speech, but rather because of the affective intonation of the words.
It is also known that it can perceive the sounds of the outside although muffled by the amniotic fluid. Since the hearing organ is very sensitive, it is recommended that pregnant women do not expose themselves to loud sounds such as very loud screams, blows, very loud music ... to avoid damage.
After birth, the baby goes from aquatic listening to aerial listening. The ear canal is protected by remains of amniotic fluid and by a gelatinous tissue that will be reabsorbed over time.