| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a signal processing apparatus that amplifies an analog audio signal to a desired level while suppressing noise and an increase in circuit scale, and a signal processing method. <P>SOLUTION: A signal processing apparatus includes: a microphone amplifier 12 for amplifying a level of an analog audio signal input from the outside with a first gain which is variable; a PGA 14 for amplifying the level of the analog audio signal amplified by the microphone amplifier 12 with a second gain which is variable; an ADC 16 for converting the analog audio signal amplified by the PGA 14 into a digital audio signal; and an ALC 18 which detects a level of the digital audio signal converted by the ADC 16, and controls the level of the first gain and the magnitude of the second gain, in accordance with the detected level, in such a way that the level of the analog audio signal input to the ADC 16 becomes a predetermined level. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
