Apparatus for automatically adjusting amplitude of audio signal based on background

The invention is to provide an apparatus that is adapted to adjust the amplitude of an audio signal based on the background. The apparatus according to a preferred embodiment of the invention, the apparatus includes an audio receiving module. The audio receiving module is adapted to receive a first audio and a second audio, and generate a process signal including a first signal and a second signal. A processing module extracts the second signal from the process signal. An adjusting module receives the extracted second signal and generates a gain in accordance with the extracted second signal and a criterion. The adjusting module adjusts the amplitude of the audio signal in accordance with the gain.