Abstract This study investigated 7-month-old infants' ability to relate vowel sounds with objects when intersensory redundancy was present versus absent. Infants ( N= 48) were habituated to two alternating video-films of vowel-object pairs in one of three conditions. In the moving-synchronous condition, where redundancy was present, the movement of one object was temporally coordinated with the spoken vowel /a/ and that of the other with /i/, simulating showing and naming the objects to the infant. In the still and in the moving-asynchronous conditions, where redundancy was absent, infants saw static objects, and objects moving out of synchrony with the vowel sounds, respectively. The results indicated that infants detected a mismatch in the vowel-object pairs in the moving-synchronous condition but not in the still or the moving-asynchronous condition. These findings demonstrate that temporal synchrony between vocalizations and the motions of an object facilitates learning of arbitrary speech-object relations, an important precursor to the development of lexical comprehension in infancy.