When a ysoki is holding items in his cheek pouches, can others tell if they have something in there?

The rules on ysoki cheek pouches are rather vague on whether objects held inside them are actually concealed. It seems possible that someone else would be able to determine that the ysoki was concealing something either by visible bulge or by the impact the object has on the ysoki’s speech. Is there any published Starfinder source that addresses this question? If not, is there anything about rodent biology that suggests a good ruling?