19. The medium of claim 18 , wherein the instructions further cause the device to: responsive to the wake up command, instantiate a second speech recognition process by the device, the second speech recognition process operating on the buffered audio samples that correspond to the recognized speech element and audio samples that follow the audio samples that correspond to the recognized speech element, wherein the second speech recognition process is more sophisticated than the speech recognition performed using the vocabulary.
32. The medium of claim 19 , wherein the speech recognition performed using the vocabulary is performed by the processing device under a first power consumption constraint, and wherein the more sophisticated second speech recognition is performed using the same or a different processing device under a second and less restrictive power consumption constraint.