People with dyslexia struggle to recognise familiar voices, scientists suggest.
The finding is the first tentative evidence that small sounds in the human voice that vary between people are difficult for dyslexics to hear.
Writing in the journal Science, the scientists say that many people could have some degree of "voice blindness".
And by studying it, scientists hope to better understand how the human brain has evolved to recognise speech.
Humans rely on small sounds called phonemes to tell one person from another.
As we first try to form the word dog, for example, phonemes are the "duh"-"og"-"guh" sounds that our parents prompt us to make.
But as we master the ability to read, we become less reliant on recognising these sounds to read, and eventually stop noticing them.
Despite ignoring them, however, phonemes remain important for voice recognition.
The tiny inflections in the way people pronounce phonemes gives a listener cues to tell one voice from another.
Because people who suffer from dyslexia are known to struggle with phonemes when reading, a US-based team of scientists wondered whether they might also struggle hearing them in people's voices.