Do increasing numbers of women in Congress lead to more representation of women’s voices during the legislative process? Using committee hearing transcripts from 1995- 2017, we analyze how increasing the proportions of women interacts with measures of perceived power to affect a member’s participation in their committee by gender. In line with extant findings emphasizing the moderating effects of institutions, we find that increasing the proportions of women positively affects participation among majority-party and senior-ranking women. We then investigate the effect on measures of influence. Both women and men are less likely to interrupt others when women’s proportion on a committee increases. Further, women are more likely to stay on the same topic as other women, while men are likely to change topics introduced by women. Our results show that increasing proportions of women work together with individuals’ power status to increase women’s voice and shift power dynamics within Congress.