One of the key challenges in Information Literacy (IL) teaching in higher education is ensuring student engagement. As such, active learning approaches are encouraged in order to maximise student participation and interaction with the teaching. The use of audience response systems (ARSs) is one active learning approach which is being used increasingly in IL teaching. The purpose of this study is to investigate the effectiveness of ARSs in terms of increased engagement and student learning. Previous research has explored the use of ARSs as an active learning approach in comparison to traditional lectures, but this study aims to specifically examine the effectiveness of these tools as part of an active learning pedagogy. Most existing studies have looked at a single ARS, usually clickers. With an increase in availability and functionality of online tools, and discussions at a university level about moving to a single system which makes use of students' own devices, this study also aims to compare the effectiveness of clickers and online ARSs. A controlled study was carried out on two cohorts of medical students at Queen Mary University of London comparing the use of clickers, online response tools, or a mixture of the two, to teaching without ARSs. Class observation and student evaluation were used to measure student engagement, and quizzes and student confidence levels to measure student learning. Results of the study showed that ARSs, when used as part of an active learning pedagogy, are an effective tool in terms of increasing student engagement, and have a generally positive impact on student learning, with online tools being slightly more effective than clickers. The study provides evidence which can be used by IL practitioners to help integrate ARSs into their teaching as well as inform institutional decisions on the use of these tools.