5. A method comprising: producing, by a speaker included in an audio device, output audio in a user environment; receiving, from a microphone array of the audio device, a plurality of audio signals representing input audio; generating, for each of the plurality of audio signals, a recognition parameter indicating whether a corresponding audio signal includes a predefined expression; identifying, based at least in part on the recognition parameters, two or more audio signals, of the plurality of audio signals, that include the predefined expression; determining that a total number of the two or more audio signals is more than a threshold number; and based at least in part on the determining that the total number of the two or more audio signals is more than the threshold number, determining that an occurrence of the predefined expression in the input audio is a result of the predefined expression occurring in the output audio from the speaker.
5. A method comprising: producing, by a speaker included in an audio device, output audio in a user environment; receiving, from a microphone array of the audio device, a plurality of audio signals representing input audio; generating, for each of the plurality of audio signals, a recognition parameter indicating whether a corresponding audio signal includes a predefined expression; identifying, based at least in part on the recognition parameters, two or more audio signals, of the plurality of audio signals, that include the predefined expression; determining that a total number of the two or more audio signals is more than a threshold number; and based at least in part on the determining that the total number of the two or more audio signals is more than the threshold number, determining that an occurrence of the predefined expression in the input audio is a result of the predefined expression occurring in the output audio from the speaker. 7. The method of claim 5 , further comprising: determining that the two or more audio signals and a reference signal set have the same one or more members, wherein the reference signal set has one or more members comprising one or more of the audio signals that contain the predefined expression during an occurrence of the predefined expression in the output audio, wherein the determining that the occurrence of the predefined expression in the input audio is the result of the predefined expression occurring in the output audio from the speaker is based at least in part on the determining that the two or more audio signals and the reference signal set have the same one or more members.