Systems and methods for generating and performing a three-dimensional audio CAPTCHA are provided. One exemplary system can include a decoy signal database storing a plurality of decoy signals. The system also can include a three-dimensional audio simulation engine for simulating the sounding of a target signal and at least one decoy signal in an acoustic environment and outputting a stereophonic audio signal based on the simulation. One exemplary method includes providing an audio prompt to a resource requesting entity. The audio prompt can have been generated based on a three-dimensional audio simulation of the sounding of a target signal containing an authentication key and at least one decoy signal in an acoustic environment. The method can include receiving a response to the audio prompt from the resource requesting entity and comparing the response to the authentication key.