What does this icon stand for in the settings pull down?

[AC Question]

I just got a Alcatel Sonic and it is running 4.1.2.
When I pull down the menu from the top, I see all my options to turn things off and on (airplane mode, wifi, etc). I know all of them except the last one on the right. It looks like a phone. When I click it, it puts a 1m right in the middle of the phone icon. I am assuming I am turning something on when the 1m appears but I have no clue what it could be.

 

[anon8380037]

Hello. My first guess would be an audible minute minder durung a call. You should be able to Google for a manual.
I haven't heard of it on other devices.
I just wanted to show how clever I think I am.