Critical periods and adult language learning: what closes and what stays open
September 28, 2026 · 17 min read
Eddie Chang, Erich Jarvis and Huberman describe early windows for speech and accents, yet also show adults can still learn languages and skills through focus and effort. It sets realistic expectations for adult learners without telling them it is too late.
The rules, numbers and steps worth keeping in front of you.
- Core message for adults: not too late, but different rules.
- Eddie Chang: babies lose sensitivity to non-native speech sounds within a couple of years.
- Chang: earlier and more immersive is better; keep exposure going or lose it.
- Chang: live human interaction matters more than recordings.
- Erich Jarvis: speech has a stronger critical period than other skills; accents are easiest to avoid early.
- Jarvis: already speaking several languages makes new ones easier, though some dispute this.
- Huberman: children learn from passive exposure; after about 25, learning takes deliberate focus.
- Huberman: no alertness, no neuroplasticity; attention is what opens adult change.
- Huberman: the rewiring happens during sleep, so rest after hard sessions.
- Learn in small increments; cramming a lot in one bout is a mistake for adults.
- Errors are the signal for change; stay with them for about 7 to 30 minutes.
- Real stakes speed adult learning.
- Give special practice to sounds your native language lacks.
- Children with hearing loss, speech delay or a stutter: see an audiologist or speech-language therapist.
This is the short form. The full insight has every expert's reasoning, their own words and the sources.