Purpose of the paper:To understand the "black box" of boardroom behavior, we test the impact of different thresholds of female directors on a set of board processes. Using the two percentages indicated by the gender quota law, we distinguish between two possible situations that women face: (1) voicing of women's opinions, and (2) having their voices heard. Methodology: We employ an econometric model to test our research question on a sample of all of the 40 Italian companies listed in the FTSE-MIB between the years 2008 to 2015,Findings: We provide evidence that when women voice to their opinion (i.e. they are represented by at least 20% of the board seats), boards devote more time to their activities, and the cognitive conflicts among members is enhanced. However, when women's voice are heard (i.e. when the threshold of at least 33% of women is reached), boards increase the directors' attentiveness, and women become particularly effective in boosting the cognitive conflicts.Research limits: In our analysis we use proxies of board behaviour that are built from secondary data.Practical implications: Our findings provide insights which have implications for gender quota regulation, and offer a new understanding of the contribution of women at decision-making position levels.Originality of the paper: We further develop the critical mass theory in the context of women on boards, focusing on two different situations that women might face. We analyse the channel variables between women on boards and corporate governance, investigating board behaviour and board dynamics.