AUTOMATIC VOLUME CONTROL-SYSTEM FOR COMPENSATION OF VOLUME DIFFERENCEBETWEEN TV CHANNELS

The sound levels of TV channels vary greatly according to modulation a nd demodulation rates. When the television channel or input mode is ch anged, users have to adjust the volume in order to obtain a proper lev el of sound. In this paper, an automatic volume control system is prop osed to compensate for the volume difference which occurs with channel changing. A simple power estimation based on the symmetry property of sound and a selective volume control algorithm using a 3-step compens ation are presented. The proposed system is designed using consumer IC s for easy implementation to current audio media. In addition, a filte r is used to revise the system function in order to model the frequenc y response of the designed system upon that of human at a normal heari ng level. As the experimental results in TV set, it is shown that the volume fluctuation is considerably reduced.