1. A computer-implemented method comprising: receiving, by a mobile computing device that is operating in a sleep mode, sounds corresponding to a beginning portion of a predetermined hotword that is associated with waking the mobile computing device to an awake mode; and before receiving sounds corresponding to a remaining portion of the predetermined hotword that is associated with waking the mobile computing device to an awake mode, initiating, by the mobile computing device, processing to begin waking the mobile computing device to the awake mode without initiating processing to complete waking the mobile computing device to the awake mode.