Relation of melody complexity in infants' cries to language outcome in the second year of life: A longitudinal study

This study is part of the German Language Development Study's prospective longitudinal research programme on infants from birth until the age of 3 years. Thirty-four infants were retrospectively classified into two groups (normal/delayed) by their language skills at 2.5 years of age. Frequency spectrograms and melodies of about 11,000 cries from the first 16 weeks of life were analysed using a CSL 4400. A Melody Complexity Index was calculated at monthly intervals. Infants with less than 45% complex melodies in their cries during the second month were found to be almost five times more likely to develop a language delay as infants with a higher proportion. For infants above the cut-off of .45, development of a language delay condition could be ruled out with a probability of 89%. Although the results need to be interpreted cautiously, the data indicate a possible relation between early melody development and later language outcome.