Jona Greve, Edda van Meurs and Bernd Strauss have addressed this question in their recently recently published study "Elite darts performance and the social influence of real crowds and simulated crowd noise" in Nature's prestigious journal “Scientific Reports”. The article analyses darts performance in the absence of crowds and the effects of a live audience or simulated crowd noise in world class darts players and finds that although the performance of elite darts players is diminished by cheering spectators, this effect is rather small.