To extract only the voice of a speaker from sound receiving signals including the voice of the speaker and noise by providing a second sound receiver for receiving only the sound which is produced by vibration of a human body generated with vocalization of a speaker.

When a speaker vocalizes under a noisy environment, a first microphone 1 receives aural signals including the voice of a speaker and noise. Meanwhile, a second microphone 3 receives the sound produced by vibration of the eardrum of the speaker. A soundproof material prevents the environment noise from being received by the second microphone 3. The second microphone 3 thus receives the sound produced by the vibration of the eardrum of the speaker. A voice extraction part 6 extracts only such signals as having strong correlation with the output signals (b) of the second A/D converter 5, which converts the input signals of the second microphone 1, from among the output signals (a) of the first A/D converter 2 which converts the sound receiving signals of the first microphone 1. This constitution can extract only the voice of the speaker.