| 摘要 |
PURPOSE: To allow the user to listen to a sound close to an original audio signal by eliminating noise in a cabin. CONSTITUTION: A microphone 15 monitors a sound in a cabin and an adder 18 extracts only noise in the cabin. A frequency analyzer 19 obtains a frequency spectrum of the noise in the cabin. A controller 20 obtains a frequency (at a peak level) and its level of the noise in the cabin based on the frequency spectrum. Furthermore, the controller 20 determines a gain of an audio signal by taking a masking effect being a characteristic of a human audible sense into account. An equalizer 11 corrects the frequency characteristic of the audio signal based on the gain. |
