What is that interface near the bottom of my phone's back?

[ChiefDog]

S5. Bottom of back.

 

[Chris5483]

Without actually having the phone, If what you're talking about is in this picture I'm guessing it's the noise cancellation microphone.

 

[ChiefDog]

Yes. Thanks

 

[L0n3N1nja]

All I see near the bottom is the speaker.

 

[belodion]

^ Same here.