Audio processing apparatus and method for audio processing

A method of processing audio, comprising:

• processing an audio input by a signal processing circuit to generate an audio signal, wherein processing the audio input by the signal processing circuit to generate the audio signal comprises selectively attenuating the audio input or by adjusting magnitude of one or more frequency components in the audio input;
• receiving an operating voltage;
• obtaining a volume value from the audio signal;
• comparing the volume value with a first volume threshold to generating a comparison result;
• in response to the comparison result, setting the operating voltage to have a corresponding one of a plurality of voltage levels;
• and
• driving a load circuit by a power amplifier according to the audio signal.

An audio processing device, comprising:

• a signal processing circuit, configured to process an audio input to generate an audio signal;
• a power amplifier, comprising:
• a modulator, coupled with the signal processing circuit, configured to generate a PWM signal and also configured to determine a duty cycle of the PWM signal according to the audio signal;
• and
• a plurality of output stage circuits, coupled with the modulator and a detection circuit, configured to receive a plurality of operating voltages, respectively, and also configured to receive the PWM signal, wherein the plurality of operating voltages have respective voltage levels different from each other;
• and
• the detection circuit, coupled with the signal processing circuit and a power switch circuit, configured to obtain a volume value from the audio signal, configured to compare the volume value with a first volume threshold to generate a comparison result, and configured to enable, according to the comparison result, a corresponding one of the plurality of output stage circuits to drive a load circuit.