When too many vowels impede language processing: An eye-tracking study of Danish-learning children

Research has suggested that Danish-learning children lag behind in early language acquisition. The phenomenon has been attributed to the opaque phonetic structure of Danish, which features an unusually large number of non-consonantal sounds (i.e., vowels and semivowels/glides). The large amount of vocalic sounds in speech is thought to provide fewer cues to word segmentation and to make language processing harder, thus hindering the acquisition process. In this study, we explored whether the presence of vocalic sounds at word boundaries impedes real-time speech processing in 24-month-old Danish-learning children, compared to word boundaries that are marked by consonantal sounds. Using eye-tracking, we tested children’s real-time comprehension of known consonant-initial and vowel-initial words, when presented in either a consonant-final carrier phrase or in a vowel-final carrier phrase, thus resulting in the four boundary types C#C, C#V, V#C, and V#V. Our results showed that the presence of vocalic sounds around a word boundary—especially before—impedes processing of Danish child-directed sentences.