Overtly presented, but ignored visual stimuli are inhibited in a later recognition task if previously presented synchronously with an attended visual target. Here, we extend these findings to auditory presentations. Participants were required to respond to immediate sound repetitions in a stream of simultaneously presented spoken words, and later given a surprise recognition test that measured recognition for the unattended words. Words that had been simultaneously presented with a sound repetition in the previous repetition detection task were later recognized at levels significantly below chance. These data suggest the existence of an inhibitory mechanism that is exhibited in later recognition tests for salient auditory information that was previously unattended and had been simultaneously presented with an attended auditory target in a separate task.