Function Explanation：
Double mic noise reduction refers to mobile handsets is equipped with two microphones, one is used to keep a clear call, the other one for physical noise cancellation.
Collect the voice of the outside world, then release noise sound waves that is opposed, at last eliminate the noise through the offset principle, so that can maintain
good call quality even in many noisy place. The basic idea is the same as opening mouth to reduce the pressure on eardrum when hear a shot.
Notes:
One of the reasons for the low voice may be that the voice source is far away from the main microphone, and the voice is collected by the main microphone and the
secondary microphone at the same time, and treated as noise. Therefore, the voice is low, which can be solved by appropriately adjusting the voice posture.