Android HDMI connection AND Microphone, is it possible?

[AC Question]

Hello, I’m trying to connect an android tablet (Sony Xperia Z2) to an HDMI display (LG 43UH6500) for an exhibition project.
In order to do this, I’m using an MHL cable, and so far there are no issues with the picture or sound via HDMI.
However, the app I want to show requires input via a microphone, so I wanted to use an external mic in order to have a better reach than the internal one.

I got an external microphone for tablets/smartphones, but when I connect it, the sound mutes on the TV.
I want to have the sound and picture on the TV (or external speakers) and also be able to use the external microphone. Is there a way to do this?

So far I have tried:
-Using an application called SoundAbout: when the mic is connected I can set the audio output to the TV, but then the mic stops working.
-Got a cable that divides audio/mic so I could connect the mic in one end and speakers in the other. Doesn’t work either.

Does anyone know how to go around this issue? Thank you in advance.

 

[jasonandrews25788]

I think this happens beacause of the app itself.
to be more specific it gains the AudioFocus of the System.
if you're the developer of the app read the documentation:
https://developer.android.com/reference/android/media/AudioManager.html

 

[Ume13]

Thank you for your response, I will look into it.
However, it is not an issue of only the app, every sound in the tablet behaves in the same way.