What's the icon of a phone with signal bars in the right hand corner of an ZTE phone

[Android Central Question]

Right beside the 4G data icon is a phone which has 2 bars coming out of the top of it. Since this icon has appeared I have no volume for anything on my phone. What do I do to resolve this issue.

 

[tony bag o donuts]

I think it means the speaker is on.
Have you rebooted the device?

I will check my kids' zte 7's when I get home later tonight.

 

[Rukbat]

A phone with 2 things like "rabbit ears" (if you remember the old days of TV)? That sounds like Wifi calling. It wouldn't have any effect on audio in general.