At just four months of age, infants develop the ability to perceive language details, according to a new study led by linguist Eylem Altuntas. This research outlines the mechanisms by which the young human brain learns to distinguish individual sounds.
Altuntas describes children as "little detectives" who constantly gather clues about their surroundings. She notes that this ability begins much earlier than previously thought, challenging the established belief that children tune into their native language between six and twelve months of age.
By the time infants reach their first birthday, their hearing is attuned to their mother tongue, a process linguists refer to as perceptual tuning. During this phase, the brain categorizes sounds and focuses on those deemed most important.
In the first six months of life, infants can differentiate sounds from languages they have never heard before, such as specific contrasts in Hindi or unique tones in Mandarin, even if they grow up in an English-speaking environment. This remarkable ability diminishes as children begin to specialize in the sounds they hear most frequently between six and twelve months. Vowel tuning starts around six months, while consonant tuning occurs after ten months.
Altuntas's study, published in the journal Developmental Science, contributes to understanding how individuals acquire their primary communication tool and aims to aid children at risk of speech developmental delays.