Speech consists of a continuous stream of acoustic signals, yet humans can segment words from each other with astonishing precision and speed. To find out how this is possible, a team of linguists has analysed durations of consonants at different positions in words and utterances across a diverse sample of languages. They have found that word-initial consonants are, on average, around 13 milliseconds longer than their non-initial counterparts. The diversity of languages for which this effect was found suggests that this might be a species-wide pattern -- and one of several key factors for speech perception to distinguish the beginning of words within the stream of speech.