english: Researchers take advantage of this fact by rigging up two rubber nipples, so that if a baby sucks on one, it hears a recording of its mother's voice on a pair of headphones, and if it sucks on the other nipple, it hears a recording of a female stranger's voice.
non_english: Raziskovalci izkoriščajo to dejstvo tako, da uporabijo dve gumijasti bradavici: ko dojenček sesa eno, sliši posnetek materinega glasu skozi slušalke; ko sesa drugo bradavico, pa sliši posnetek tujega ženskega glasu.