Infancy and Fast-changing Sounds (IMAGE) Boston Children's Hospital Caption Syllables contain fast-changing sounds. The maps above show how the syllables /ba/ and /da/ sound in normal speech. The graphs show the pitch over time. In this example, the part of the sound that changes quickly is the consonant at the beginning. In /ba/, the pitch of /b/ rises quickly--over tens of milliseconds--from between 500 and 1,000 Hertz to between 900 and 1,200 Hertz. The pitch of /d/ in /da/ changes just as quickly, but in a different pattern. If infants can't capture the details of these patterns, they can't understand the differences between the syllables "ba" and "da" and may confuse them (even before they learn to read). Learning the sounds of other syllables involves making other fast-sound computations, like measuring silences between syllables lasting minute fractions of seconds. In infancy, children with a higher risk of developmental dyslexia may not be able to capture these details because their brains process fast-changing sounds in the wrong way. Credit Image excerpted from: Tallal P. Improving language and literacy is a matter of time. Nat Rev Neurosci. 2004 Sep;5(9):721-8. Usage Restrictions Consult journal publisher. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.