What are the cues that infants use to segment vowel-initial words?

In this experiment, babies listened for a minute or two to a passage.  Then, we played them words that were present in the passage and words that were not.  If babies correctly segment the words, they are expected to listen longer to words present in the passage.  We asked if 11-month-olds who have a hard time segmenting words that begin with vowels (e.g. ash), can do so when these words follow a highly frequent function word, such as “the.”

The results of this study demonstrate that 11-month-olds, but not 8-month-olds, are able to use the frequently occurring function word “the” to segment vowel-initial words.  This suggests that function words are known words for infants, and 11-month-olds are able to use this “known word” to find other words in a passage.