We conduct two crowdsourcing experiments designed to examine the usefulness of audio cocktails to quickly find out information on the contents of large audio data. Several thousand crowd workers were engaged to listen to audio cocktails with systematically varied composition. They were then asked to state either which sound out of four categories (Children, Women, Men, Orchestra) they heard the most of, or if they heard anything of a specific category at all. The results show that their responses have high reliability and provide information as to whether a specific task can be performed using audio cocktails. We also propose that the combination of crowd workers and audio cocktails can be used directly as a tool to investigate the contents of large audio data.