An audio processing system is provided with a speaker, a plurality of microphones, and an audio processing device. The audio processing device includes a plurality of filters that allow audio signals of audio collected by the plurality of microphones to pass any respective first bands included in a band of the audio output from the speaker, a plurality of delayers that delay the audio signals passed through the plurality of filters by delay times corresponding to the first bands respectively, a correlation value calculator that calculates a correlation value of a plurality of audio signals delayed respectively by the plurality of delayers and an audio signal of the audio output from the speaker, and a determinator that determines presence or absence of abnormality in the plurality of microphones and the speaker based on the correlation value.