Although children as young as 49 hours can match up the number of sounds with the number of objects, they can only do so at certain ratios. When 1:3 ratios were used (4 sounds and 4 objects or 12 objects), around 90% of the infants paid more attention to the corresponding image thus showing their recognition. However, when 1:2 ratios were used, only 68% of infants showed recognition of the correct corresponding image. This tells us that although infants can recognize corresponding numbers of sounds and objects, the two images of objects must be visibly different - one must have a much larger number of objects, or a much smaller number of objects.