Rear microphone not detected I purchased a few lapel microphones to test out for recording my talks at conferences using my android device. These mics are all mic-only devices, not headphone or head-set units. 

The issue is that the microphone, when plugged in, will be detected by the OS as ear-phones/headset on some older devices like an S4, while on newer devices like the G4, it will be seen as 'Microphone'.

The issue is that in the app I'm using, the only microphone that gets picked up is the front mic (the mic on the phone) and never my plugged-in microphone. There is a setting in the app to choose which mic to use, I select Rear Mic, but it says it will only be used, "when detected". 

This is my problem, it doesn't seem to be detecting anything. If I plug in headset (ear-buds with a mic), I can record from that mic no problem.

How do I configure the OS to recognize the lapel microphones so I can use them? 

I have tried a few adapters that came with the mics, nothing worked. On the G4 the only difference I saw was that using an adapter would make it see a headset or microphone, but the result of not picking up audio from the mic was the same. 

I've tried 6 different microphones and yes, they were all intended to be used on android/ios devices
From the following article, it could be due to need for an impedance (a resistor) between the Mic and the Ground wires. As per


  The trick in detecting the external microphone on the smart phone is
  to have right impedance between the mic pins. Samsung phones seem to
  require a microphone with impedance of around 1.0k – 1.5k Ohm. Some
  other devices might also work with somewhat higher resistance values
  (1 kohm to few kilo-ohms).


I don't think it's a matter of altering the OS as detection is probably reliant upon the physical/electronic components used.

The article explains that there are two standards used for 4 pin OMTP and AHJ. It also has links to some articles about how to connect (aka DIY wiring/rewiring).

Here's a link to the article. 

Android device external mic wiring

I don't think that it's a matter of changing the OS, rather catering for the specific components used.