LEVEL ADJUSTMENT CIRCUIT, DIGITAL SOUND PROCESSOR, AUDIO AMPLIFIER INTEGRATED CIRCUIT, ELECTRONIC APPARATUS, AND AUTOMATIC LEVEL ADJUSTMENT METHOD OF AUDIO SIGNAL

摘要

PROBLEM TO BE SOLVED: To provide a level adjustment circuit of which the sound quality is improved.SOLUTION: A level adjustment circuit 10 automatically adjusts a level of an input audio signal S1. A filter 16 receives the input audio signal S1 and passes a band set to each input audio signal. A DRC circuit 30 is configured to amplify a signal from the corresponding filter 16 and to automatically adjust a gain in such a manner that a signal level of output does not exceed a predetermined threshold level. An adder 18 adds output signals of N pieces of DRC circuits 30. A band pass filter 22 extracts a band including a corresponding crossover frequency from an output signal of the adder 18. A gain correction part 24 is configured to correct at least one gain of the corresponding DRC circuit in accordance with the signal level of output from the corresponding band pass filter 22.