Vowel bias in Danish word-learning: processing biases are language-specific

Discriminiationi of synthetic speech sounds was studied in 1- and 4-month-old infants. The speech sounds varied along an acoustic dimension previously shown to cue phonemic distinctions among the voiced and voiceless stop consonants in adults. Discriminability was measured by an increase in conditioned response rate to a second speech sound after habituation to the first speech sound. Recovery from habituation was greater for a given acoustic difference when the two stimuli were from different adult phonemic categories than when they were from the same category. The discontinuity in discrimination at the region of the adult phonemic boundary was taken as evidence for categorical perception.

The main objective of this paper is to describe the trajectory of Danish children's early lexical development relative to other languages, by comparing a Danish study based on the Danish adaptation of The MacArthur-Bates Communicative Development Inventories (CDI) to 17 comparable CDI-studies. The second objective is to address the feasibility of cross-linguistic CDI-comparisons. The main finding is that the developmental trend of Danish children's early lexical development is similar to trends observed in other languages, yet the vocabulary comprehension score in the Danish children is the lowest across studies from age 1 ; 0 onwards. We hypothesize that the delay is related to the nature of Danish sound structure, which presents Danish children with a harder task of segmentation. We conclude that CDI-studies are an important resource for cross-language studies, but reporting of studies needs to be standardized and the availability of published data improved in order to make comparisons more straightforward.