This study explores how stereotypical preconceptions about gender and conversational behaviour may affect observers' perceptions of a speaker's performance. Using updated matched-guise techniques, we digitally manipulated the same recording of a conversation to alter the voice quality of "Speaker A" to sound "male" or "female." Respondents' perceptions of the conversational behaviour of Speaker A in the two guises were then measured with particular focus on floor apportionment, interruptions and signalling interest. We also measured respondents' explicit stereotypical gender preconceptions of these aspects. Results showed that respondents perceived the male guise as having more floor apportionment and interrupting more than the female guise. Results also indicated that the respondents had explicit stereotypes that matched these patterns, i.e. that interrupting and taking space were deemed to be stereotypically male behaviour, while signalling interest was deemed to be a female feature. The study suggests that stereotypical preconceptions about gender and conversational behaviour may skew perceptions of similar linguistic behaviour.