Five humans were exposed to a matching to sample task in which the delay (range = 0 to 32 seconds) between sample stimulus offset and comparison onset was manipulated across conditions. Auditory stimuli (1” tone) and arbitrary symbols served as sample stimuli for three (S1, S2, S3) and two (S4 and S5) subjects, respectively. Uppercase English letters (S, M, and N) served as comparison stimuli for all subjects. Results show small but systematic effects of the retention interval on accuracy and latency to selection of comparison stimuli. The results fail to show a difference between subjects exposed to auditory and visual sample stimuli. Some reasons for the failure to note a difference are discussed.