The Rose Connect software that you use to run the RS150B, either from an Ipad, I Phone, Computer (Mac or PC) or Android tablet or phone. In the upper righthand corner of the applicatin (client), there is an icon that looks like a remote control (will have a green dot next to it if it is connected). If you touch the remote icon, you will come to the remote control page. In the middle of the page, it says your model name/unit name(in my case RS150B). and directly below that in the same text box is a volume slider with the mute button on the far right. If it is muted, that mute button will be highlighted golden brown.