Patent ID: 8606381

Claim:
A method for switching audio recording modes, the method comprising: receiving an audio signal; determining a current audio recording mode being one of a low sensitivity audio recording mode and a high sensitivity audio recording mode; routing the audio signal to a first signal path according to the current audio recording mode, wherein each of the first and second signal paths includes an analog-to-digital (ADC) and an automatic gain controller (AGC); obtaining a digital gain from the first signal path for digital audio recording data in the current audio recording mode; and switching to route the audio signal to the second signal path when the digital gain reaches a gain threshold, wherein when the current audio recording mode is the low sensitivity audio recording mode, the method further comprises: amplifying the audio signal according to a first analog gain of a sensitivity switch; converting the amplified audio signal to digital audio recording data; and amplifying the digital audio recording data according to the first digital gain of the automatic gain controller in the first signal path; wherein when the current audio recording mode is the high sensitivity audio recording mode, the method further comprises: amplifying the audio signal according to a second analog gain by the sensitivity switch; converting the amplified audio signal to digital audio recording data; and amplifying the digital audio recording data according to the second digital gain of the automatic gain controller in the second signal path; wherein the second analog gain is larger than the first analog gain; wherein when the low sensitivity audio recording mode is switched to the high sensitivity audio recording mode, the method further comprises: informing the sensitivity switch to substitute the second analog gain for the first analog gain; and starting the automatic gain controller in the second signal path after delaying a first predefined number of frames in the audio signal; wherein when the high sensitivity audio recording mode is switched to the low sensitivity audio recording mode, the method further comprises: informing the sensitivity switch to substitute the first analog gain for the second analog gain; and starting the automatic gain controller in the first signal path after delaying a second predefined number of frames in the audio signal; and wherein the second predefined number is larger than the first predefined number.