1. A method for responding in an augmented reality (AR) application of a mobile device to an external sound, the method comprising: detecting a target via an image sensor of the mobile device; initiating a virtual object in the AR application and positioning the virtual object at a position corresponding to a location of the target based on detecting that the target satisfies an AR application initialization criterion; receiving, by at least one sound sensor of the mobile device, the external sound from a sound source; determining, at the mobile device, first geometric information that includes a first direction between the sound source and the target, the first direction different than a second direction between the target and the mobile device; and causing the virtual object to perform, in the AR application, at least one response to the external sound based on the first geometric information.