From mouth to mind: Interfaces of internal speech and the end of language as a barrier

For two decades, we've treated language as a human input/output problem: fingers to type, lungs and lips to speak, and years of training to master a second language. That design hypothesis has just been broken. In August 2025, a team led by Stanford reported a brain implant that decoded "internal speech" — silent, self-generated words — at the command with up to 74% accuracy from a vocabulary of 125,000 words,  protected by a thought password that prevented accidental decoding in about 98% of cases.