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How babies develop hearing and understanding

Psychology of Sound: How babies develop hearing and understanding

The first year of a baby's life is the most important in terms of development, and it's a fascinating time to learn about when considering the psychological implications of how our little ones understand and interpret the world around them. Hearing is the second of the five senses that your child will develop, and one of the most important for communication - so hopefully, this guide should give you a better understanding of how hearing develops, and how our children learn to react to different sounds in their environment!

First sounds

The way a child reacts to sound is often determined by its early experiences as a foetus, so we'll start by taking a look at just how and when hearing starts, and what kinds of sounds can be heard in the womb.

Hearing development

The hearing organs start forming when a foetus is just three weeks old, starting at the inner ear and slowly building up to the ear canal, until eventually you'll be able to see the outer ears on an ultrasound image. This happens quite quickly - it's thought the auditory system becomes functional at around 25 weeks - so there's plenty of time for them to get used to the many noises detectable within the womb!

Hearing development also improves as the brain becomes more complex - any sounds the foetus hears will be created as new memory circuits, creating meaningful associations with each. A foetus can detect different moods and emotional responses to speech and music at around 36 weeks old, and will soon learn to distinguish between happiness, sadness, anxiety and peace.


What a foetus hears

By inserting a small hydrophone into the uterus of a pregnant woman, researchers have found that even in calm, quiet environments the background noise in the womb is similar to that of a house or apartment. Common sounds included whooshing noises as the blood moves through adjacent vessels, gurgling from the stomach, and of course the heartbeat of the mother. The foetus can also hear the mother's speech, and will start tuning in to the voice, language and intonation - a feat that will have an impressive bonding effect between mother and baby once the child is born.

A number of studies have been carried out on foetuses to find out exactly how they interpret sound while in the safety of the womb. We can detect reactions in the third trimester by monitoring the heartbeat under different conditions. This allows us not only to discover when the baby is agitated - for example by sudden noises - but also to find out what makes them most comfortable and relaxed. Tone is particularly important at this time; studies have found that foetuses respond to changes in pitch when music is playing, and are happier when they hear their mother speaking her everyday language rather than a foreign dialect with unfamiliar intonations.


Key sounds for soothing and calming

You can use your understanding of what foetuses hear in the womb to make them more comfortable, with just a few short steps each night. This won't just relax the baby now, but will also create a set of bonding associations that will continue even after the birth, allowing you to make a connection with your baby straight away. Here are some of the best things you can do to communicate with your bump:

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Talk to them

While they won't be able to understand you, it's the tone and the comforting sound of your voice that makes this a simple yet effective way to soothe your baby during the last few weeks of pregnancy.

Read to them

Studies have shown that foetuses feel more relaxed when they are read the same book over and over again, indicating that memory is already relatively well-developed. Again, it's the tone rather than the content that counts - and your baby will have the same comforting association with the book of your choice even after birth! Do make sure you change it up occasionally though, to keep them engaged and give them plenty of new learning experiences while in utero.

Avoid placing headphones on your bump

Contrary to what you may have heard, headphones should never be placed on your baby bump - each speaker contributes the same amount of sound, meaning that while you might wear them and hear 70db in each ear, your baby will hear 120-140db. Directing sounds straight into this space can disrupt sleeping patterns and agitate your baby - it's always worth chatting to a doctor or maternity specialist, who might be able to give you an effective way of sharing music with your child.

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Hearing the world

After your baby is born, he or she will spend the first few weeks getting used to their new surroundings, and learning how to use their new sense of sight. During this time, familiar sounds and sensations are a good way of comforting them, and recreating the environment of the womb is a good way of comforting your baby when they seem agitated or overwhelmed. However, your baby's hearing will continue to develop until they are about six months old, so it's important to know exactly how it will improve and the effect this will have.

Hearing development

While your baby will already have well-functioning ears at birth, they'll continue to develop for the first six months, and you might notice in that time that your baby's preferences change. The reason for this is that they can hear a wider range of frequencies, and may be more susceptible to loud noises than they were before. The temporal lobe is also fully developing in this time, which is the part of the brain responsible for understanding sound, language and a whole host of other sensory stimuli - which is why you might find it a chore to get them to settle down in this time!

After around six months, your baby will have learned to detect where sounds are coming from, and within a year will be able to recognise and try to join in with favourite songs.

Your baby has a lot to learn in this first year - as well as the continued growth of many sensory organs, they'll also be trying to work out how to derive meaning from the sensory input around them. This can sometimes result in a little anxiety, but babies are well-prepared for this kind of sensory stimuli in their formative years, and you shouldn't worry unduly as they adapt to the world around them.


Helping your baby adjust

Sound can be used to great effect in helping your baby settle into the world, allowing them to experience the same comfort and feeling of safety that they had in utero. These are some of the best ways to achieve this:

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Cuddle your baby

As well as providing the comfort of being held, you're also giving your baby a chance to rest and listen to your heartbeat - one of the most relaxing sounds. The psychology behind this is very simple - as well as being a familiar sound, it's also a survival instinct for the baby to be comforted when they hear sounds they associate with their mother.

Read to your baby

Just as it did while you were pregnant, reading to your baby strengthens the bond between you, giving your baby a familiar routine from the voice they are most comforted by. If you read the same book to your baby bump, even better - anything that recreates that sense of being in the womb is a good way to get baby settled.

Block out other noises

If you're really struggling to get your baby to settle down, you might find that a white noise machine in the room is an effective comforter. This creates a constant noise similar to the gentle hum of the body when your baby was still in the womb, and has the



additional benefit of obscuring external noises which might otherwise disturb baby's sleep pattern. White noise machines also help to slow brainwave patterns, making them a good option for babies who are perhaps feeling overstimulated and anxious.

Language acquisition

Sound's biggest role in a baby's development is to help with language learning. Babies have an innate ability to learn languages, and in fact are more likely to be bilingual if they start hearing multiple languages from birth.

Even before they can work out the meaning of speech, babies can use the intonation to convey the same message. A study in 2009 found that babies in different countries have different cries, as a result of the different tones used between languages - for example in France, where native speakers end most sentences on a raising note, fond that babies did the same when crying out, while in Germany where speakers do the opposite, babies similarly dropped the pitch of their cries toward the end of each utterance.

Psychologists have even found that babies may start to assign emotions to sounds from a very early age -

while the generally agreed time for understanding complex emotions is about six to eight months, studies by psycholinguists and neurologists have shown that the squeaks, growls and babbles that a baby makes before that age are part of a learning process, during which time your child will start to assign certain sounds to certain emotions.

It's impossible to know how every baby will react to a world rich with sounds, voices and languages, but by watching and spending time with your baby you'll soon be able to learn how they're feeling based on the type of cry they give and the sounds they make. Equally, your own tone of voice will communicate a lot to them before they can even begin to understand what you're saying - so you can rest assured that your baby is wired to understand you when you comfort and play with them!