When are English-learning infants sensitive to the distribution of sound sequences in their native language?

In this experiment, we presented English-learning 5-month-olds with two sets of lists of monosyllables – one had English sounds that are common (e.g. boir, koof) and the other had English sounds that are uncommon (e.g., choiz, shuth). Infants were tested using the Headturn Preference Procedure[MS1] . English-learning 5-month-olds listened longer to lists with the more common English sounds, indicating that they are already familiar with the distribution of permissible sound sequences in English.