The fluency of people who stutter is affected markedly when auditory feedback is altered, suggesting that stuttering may be associated with hearing. Peripheral hearing problems, however, are no more common in people who stutter than in those who do not. Performance was investigated in a task that involves central auditory processing (backward masking). Children who stuttered had deficits in backward masking (indicated by higher thresholds) compared with a group of fluent control children. The backward-masking thresholds were positively correlated with frequency of stuttering.