This study investigates the effect of stimulus medium on recollection rate of elderly users in computer based flashcard systems. We present several rote learning tasks to 18 elderly participants with different content types and levels of difficulty. We deliver the tasks using three sorts of stimuli as visual (i.e. textonly), audio (i.e. sound-only) and audio-visual (text-and-sound). We evaluate participants' recollection rates using two memory tests, applied (i) freshly upon completing the task and (ii) after a certain time window. Our results indicate that the involvement of audio stimuli results in a higher recollection rate in both tests and a lower forget rate, specifically in relatively easier verbal content and numerical content, independent of participants' age.