Dossier: Our baby

How babies hear

Hearing is the first sense to develop in an embryo and it has an impact on your baby’s development. Your unborn child sometimes seems to dance when it hears music, voices and other sounds. When can he or she hear sounds and how does hearing develop in the following months?

Foto: Alan Pope/Unspash

Gateway to the world

From the 23rd week of pregnancy, an embryo can hear noises, particularly the sound of its mum’s heartbeat, bowels and voice. It can also hear noises from outside – your baby's ear is its gateway to the world. The abdominal wall, amniotic fluid and womb provide soundproofing, with outside noises being reduced by 20 to 30 decibels so they sound like a whisper.

How does a baby’s hearing develop?

A newborn responds to sounds that he knows, in the beginning especially his mother’s voice, but also lullabies that you sing regularly or music you listen to frequently. At 3 months, the part of your baby’s brain (temporal lobe) that supports hearing, among other things, becomes more active and more receptive. If your baby hears your voice now he will turn directly to you and answer with a gurgling sound. At 4 months your baby will respond enthusiastically to sounds and even smile when he hears your voice. He will try to copy you by saying consonants such as “B” or “M”. At 6 or 7 months your baby will be able to detect where certain noises are coming from and will turn in that direction. At around 12 months he will recognise his favourite songs and try to sing along.

How does music affect your baby?

Studies show that newborn babies clearly recognise tunes they heard in the womb. This is particularly true of songs sung by the mother, because the unborn child also feels vibrations which have a soothing effect. There is no scientific evidence documenting the number of endorphins that hearing music releases in your baby and the extent to which music has a positive impact, but that’s not particularly important. As a rule, what makes the mum happy is good for baby, too. One exception to this is excessively loud music. The general rule is, the louder the noise, the stronger the baby’s reaction. Furthermore, high frequencies can raise the heart rate, which means that you should enjoy concerts and dance clubs in moderation during pregnancy.

How can you tell whether a baby has hearing problems?

Babies aren’t usually woken by the doorbell or barking dogs because they need their sleep. However, when your child is awake and alert, she should react to sudden loud noises. Her hearing will be tested straight after birth. If you are worried about your baby’s hearing despite positive test results, you can call the medical hotline or your paediatrician at any time.