How to access the second microphone android, for example, Galaxy 3

Question

Many smartphones now have more than one microphone. One for voice input and one for reducing environmental noise.

I am wondering how can I access two microphone signals independently? Or turn off one of the microphones?

Any thoughts or comments are welcome. Thank you very much.

+6

Foreverniu Mar 14 '13 at 19:16

1 answer

Michael · Accepted Answer · 2013-03-14T19:41:07+0000

I am not familiar with the Galaxy S3 specifically, but for most of the devices that I have worked with, the following is true:

There is no reliable way to choose whether to use the primary or secondary microphone for mono recording. MIC AudioSource usually means the main microphone for monaural recording, and CAMCORDER can mean an additional microphone. But there is no guarantee for this, because it depends, for example. about the physical placement of microphones.
Recording in mono effectively mutes another microphone, and all noise reduction uses only the signal from one microphone (so there is little reduction in dynamic noise). One exception may be recording during a voice call in which both microphones are already turned on to suppress uplink noise. Another exception may be if you use VOICE_RECOGNITION AudioSource, as some manufacturers apply noise reduction to the signal using one or more additional microphones in this case.
Record in stereo from both microphones on a 2 micron device. The left channel contains the input from one microphone, and the right channel contains the input from another microphone, but there is no guarantee as to which physical microphone corresponds to the channels (again, it depends on the location).