6. A processor-implemented method, comprising: receiving, from one or more microphones, a plurality of audio signals, wherein the plurality of audio signals are processed by an audio beamformer to produce directional audio signals, wherein a first audio signal of the directional audio signals corresponds to a first direction with respect to the one or more microphones and wherein a second audio signal of the directional audio signals corresponds to a second direction with respect to the one or more microphones, wherein the first audio signal and the second audio signal emphasize sound from the first direction and the second direction, respectively; identifying the first direction as an identified direction in which a non-human sound source is located; analyzing the first audio signal to identify a representation of speech; determining that the first audio signal corresponds to the identified direction in which the non-human sound source is located; selecting a first standard to analyze the first audio signal based at least in part on the first audio signal corresponding to the identified direction of the non-human sound source; analyzing the first audio signal using the first standard to detect an utterance of a trigger expression; analyzing the second audio signal using a second standard to detect the utterance of the trigger expression, wherein the first standard includes (i) a first threshold that is greater than a second threshold associated with the second standard or (ii) a first detection algorithm that is different than a second detection algorithm associated with the second standard; and receiving, from the one or more microphones, a third audio signal including subsequent speech for performing subsequent speech recognition, based at least in part on the utterance of the trigger expression.
6. A processor-implemented method, comprising: receiving, from one or more microphones, a plurality of audio signals, wherein the plurality of audio signals are processed by an audio beamformer to produce directional audio signals, wherein a first audio signal of the directional audio signals corresponds to a first direction with respect to the one or more microphones and wherein a second audio signal of the directional audio signals corresponds to a second direction with respect to the one or more microphones, wherein the first audio signal and the second audio signal emphasize sound from the first direction and the second direction, respectively; identifying the first direction as an identified direction in which a non-human sound source is located; analyzing the first audio signal to identify a representation of speech; determining that the first audio signal corresponds to the identified direction in which the non-human sound source is located; selecting a first standard to analyze the first audio signal based at least in part on the first audio signal corresponding to the identified direction of the non-human sound source; analyzing the first audio signal using the first standard to detect an utterance of a trigger expression; analyzing the second audio signal using a second standard to detect the utterance of the trigger expression, wherein the first standard includes (i) a first threshold that is greater than a second threshold associated with the second standard or (ii) a first detection algorithm that is different than a second detection algorithm associated with the second standard; and receiving, from the one or more microphones, a third audio signal including subsequent speech for performing subsequent speech recognition, based at least in part on the utterance of the trigger expression. 9. The processor-implemented method of claim 6 , wherein: analyzing the first audio signal using the first standard comprises performing expression detection in accordance with the first detection algorithm; and analyzing the second audio signal using the second standard comprises performing expression detection in accordance with the second detection algorithm.