When answering factual questions, speakers can signal whether they are uncertain about the correctness of their answer using prosodic cues such as fillers ("uh"), a rising intonation contour or a marked facial expression. It has been shown that on the basis of such cues, observers can make adequate estimates about the speaker’s level of confidence, but it is unclear which of these cues have the largest impact on perception. To find the relative strength of the three aforementioned cues, a novel perception experiment was performed in which answers were artificially manipulated in such a way that all possible combinations of the cues of interest could be judged by participants. Results showed that while all three factors had a significant influence on the perception results, this effect was by far the largest for facial expressions.