Audio is not working for DragonBoard410c Debian (Linux)

I have Debian 16.06 (Linux) installed on DragonBoard410c and i am working on Amazon alexa voice service Setup on board but in the last step when i am speaking i am not any getting reply back.I AM HAVING A PROBLEM IN STEP 2.10.6 WHEN I AM SPEAKING AND ALEXA IS NOT ABLE TO HEAR I THINK OR IT IS not reverting back what is said.what might be the reason for this how to resolve this please help.
This IS THE LINK BELOW :
Audio Mezzanine Board - Qualcomm Developer Network .
PLEASE ANYONE HELP HOW TO RESOLVE THIS ISSUE

Thanks