unmute

I got into my Equus to drive home last night, and the stereo was on mute. There was the speaker w/ an x over it indicating mute status. However I cannot find the mute button. I am going to go check my owners manual, but any help is appreciated.

I have a 2009 Genesis 3.8 Sedan. I just bought it with 12,000 miles! Anyways, when using the navigation system aid me in arriving at my destination, the voice that tells you when to turn is muted. I can't figure out how to unmute it for the life of me! Anyone have any ideas? Thanks!