| 摘要 |
PURPOSE:To exercise accurate control by finding the area of an audio signal within a prescribed time. CONSTITUTION:An audio signal arriving via an input terminal 11 is led to an output terminal 13 via a losser 12 and also supplied to a level detecting circuit 14. The level detecting circut 14 finds the area of the audio signal and also calculates the mean value of its audio level digitally, and its output is supplied to a microcomputer 15. The microcomputer 15 discriminates between a voice and music on the basis of the output signal of the level detecting circuit 14 and then corrects a detected level according to the discrimination result. When the corrected signal goes beyond a prescribed blind sector region, a controlled variable consisting of digital bit data is generated and applied to the losser 12 via a control interface part 17. Consequently, the losser 12 is controlled to hold the audio signal at a desired level. |
