The hypothesis that male voices are more credible than female voices as narrators of instructional materials was tested with 64 randomly selected elementary school students, half of them male and half female. Students were to observe a point of light in a darkened room, and afterwards to draw a line showing how much their line moved. Four identical sets of instructions were tape recorded by male and female instructors. Responses were scored by measuring length of line in 16ths of an inch. It was shown that female students responded significantly to male voices but that males did not respond significantly by sex, although there was a slight difference in response to females. (SK)