To determine the effect of speakers' attempts to disguise their voices on listeners' accuracy in judgments of speakers' sex and race, 26 speakers, 13 women and 13 men, recorded six sentences under three conditions: (a) in a normal manner, (b) in a manner in which they attempted to sound like a member of the opposite sex, and (c) in a manner in which they attempted to sound like a member of the black race. Three master tapes were constructed, one for each of the three conditions. A total of 40 judges, 20 in an experiment on sex identification and 20 in one on race identification, participated in two sessions, one for each of two tapes (control and disguise) in each experiment. In each session they were asked to judge the sex or race of the speaker of each sentence and, using a seven-point confidence rating scale, to indicate the over-all confidence in their judgments at the end of each session. Analysis indicated that, although listeners' accuracy for sex and race identification was greater under the control than disguised conditions for the majority of speakers, the differences between the two conditions were relatively small. Implications of these findings and suggestions for future research are discussed.