How to turn on headphones mode?

[AC Question]

I turned off headphones mode, how to turn it on? Then I use headphones, everything about sound is good, it goes through headphones, but phone itself doesn't show headphone mode icon

 

[B. Diddy]

Welcome to Android Central! Which phone? Are you talking about wired or Bluetooth headphones? Wired headphones should automatically turn on the headphone mode as soon as you plug them in.