Question SOUL Electronics ST-XS2 - How to turn on Transparent Audio Mode?

[motakep701]

This is my first time to use a pair of true wireless earphones. Just got it at a great budget deal.
Love the ipx7 waterproof feature; just wanna ask if anybody know how to turn on the transparent audio mode?
And does it work in office? I need to hear other voice.

 

[americanaudiophile]

Given that the manual doesn't mention it I would guess that it's always on.