Young infants are amazing! When they are first born they can hear a wide range of sounds. Since their ears don’t know what language they will go on to learn, they are born with the capacity to learn any of them! For the first 6 months all babies have essentially the same hearing – they find some sounds easier to hear than others. For example, the ‘ee’ sound in ‘cheese’ and the ‘oo’ sound in ‘soup’ are easier to hear than the ‘a’ sound in ‘cat’. By around 6 months of age, babies’ hearing begins to change in line with the sounds they hear around them. For some sounds, babies become better at hearing differences that were originally hard to tell apart – an example of this is that American English hearing babies become better at hearing the difference between ‘r’ and ‘l’, since the language they hear around them contains lots of these sounds [1]. For other sounds, babies become worse at hearing differences between sounds that were originally easy to tell apart – an example of this is that American English hearing babies become worse at picking out the difference between two sounds in Tamil, even though the differences were initially easy to hear [2]. In this case it’s because the American babies are only hearing one of the two sounds.
This means that babies’ hearing becomes ‘tuned’ to the sensory structure of the languages spoken around them. Most of what we know about this process comes from babies hearing only one language. For these kiddies, tuning is in place by the end of the first year of life.
What about kids hearing more than one language? Surely that’s a harder process? Well guess what? Bilinguals get extra-time before the end of the language learning game – recent studies have shown that bilingual babies have an extended sensitive period compared to children hearing only one languages [3].
Image by mengyan wang from Pixabay