An audio processing apparatus comprising: a sound collector comprising a plurality of microphones [see claim 3] and configured to collect audio, which comprises utterance of a user desired to be extracted, and noise and to provide audio signals containing audio and noise; [see par. 0031, 0041] a time/frequency converter adapted to receive the audio signals from the sound collector and to provide audio signals in the frequency domain; [see par. 0064] an audio enhancer configured to enhance the audio to be extracted using the audio signals provided by the time/frequency converter; an audio attenuator configured to attenuate the audio to be extracted using the audio signals provided by the time/frequency converter; a noise environment estimator (102; 201; 301) configured to estimate a surrounding noise environment using one of the audio signals provided by the sound collector, or the audio-enhanced signal and the audio-attenuated signal, or an information input; a post-filtering unit configured to perform post-filtering processing using an audio-enhanced signal from the audio enhancer and an audio-attenuated signal from the audio attenuator, wherein the post-filtering unit is configured to set strength of processing for noise elimination according to the noise environment by the noise environment estimator; characterized by an utterance section estimator configured to estimate an utterance section within the audio signals, the utterance section comprising the utterance of the user, using the audio-enhanced signal and the audio-attenuated signal, wherein the noise environment estimator is configured to estimate the noise environment in a section estimated as a non-utterance section by the utterance section estimator. a sound collector comprising a plurality of microphones [see claim 3] and configured to collect audio, which comprises utterance of a user desired to be extracted, and noise and to provide audio signals containing audio and noise; [see par. 0031, 0041] a time/frequency converter adapted to receive the audio signals from the sound collector and to provide audio signals in the frequency domain; [see par. 0064] an audio enhancer configured to enhance the audio to be extracted using the audio signals provided by the time/frequency converter; an audio attenuator configured to attenuate the audio to be extracted using the audio signals provided by the time/frequency converter; a noise environment estimator (102; 201; 301) configured to estimate a surrounding noise environment using one of the audio signals provided by the sound collector, or the audio-enhanced signal and the audio-attenuated signal, or an information input; a post-filtering unit configured to perform post-filtering processing using an audio-enhanced signal from the audio enhancer and an audio-attenuated signal from the audio attenuator, wherein the post-filtering unit is configured to set strength of processing for noise elimination according to the noise environment by the noise environment estimator; characterized by an utterance section estimator configured to estimate an utterance section within the audio signals, the utterance section comprising the utterance of the user, using the audio-enhanced signal and the audio-attenuated signal, wherein the noise environment estimator is configured to estimate the noise environment in a section estimated as a non-utterance section by the utterance section estimator.