1. A computer-implemented method comprising: receiving audio data; determining that an initial portion of the audio data corresponds to an initial portion of a predefined phrase that is associated with waking a mobile device from a stand-by state; in response to determining that the initial portion of the audio data corresponds to the initial portion of the predefined phrase that is associated with waking the mobile device from the stand-by state, selecting a set of one or more actions that have been pre-associated with the initial portion of the predefined phrase and that are a subset of a set of actions that are associated with waking the mobile device from the stand-by state; causing the one or more actions of the set to be performed; after determining that the initial portion of the audio data corresponds to the initial portion of the predefined phrase that is associated with waking the mobile device from the stand-by state, determining that a remaining portion of the audio data corresponds to a remaining portion of the predefined phrase; in response to determining that the remaining portion of the audio data corresponds to the remaining portion of the predefined phrase, selecting additional actions of the set of actions that are associated with waking the mobile device from the stand-by state; and causing the additional actions of the set of actions to be performed.