Why cannot AudioDeviceInfo find all speakers and microphones?

[gladys0313]

Hi everyone. I'm using Nexus 6 which is specified to have 3 microphones and 2 speakers. I used the class AudioManager and AudioDeviceInfo to check the available audio devices, and what I found are:

GET_DEVICES_INPUTS: TYPE_BUILTIN_MIC, TYPE_TELEPHONY
GET_DEVICES_OUTPUTS: TYPE_BUILTIN_EARPIECE, TYPE_BUILTIN_SPEAKER, TYPE_TELEPHONY

So altogether there are 1 mic, 1 speaker, 2 telephony, and 1 earpiece.

I was wondering whether this means that there are 2 microphones and 3 speakers? And would it be possible that I can emit and record different sounds using different individual speakers and microphones simutaneously? For example, speaker 1 plays clip 1 which is recorded by mic 1, speaker 2 plays clip 2 which is recorded by mic 2....

Thanks a lot in advance!