Audio problem through Wireless headphones

I have a hearing problem listening to the the Tv so I wear wireless headphones hooked up to my Samsung 32 in Tv. I have 4 port Hdmi selector to change channels that is connected to my DVD player, Roku, WII and now Chromecast. I hear everything through the HDMI that is connected to the Roku and DVD player but nothing from the Chromecast. I am using my Samsung Tab3 and Samsung Galaxy S7 to mirror to my TV. with that I have to up the volume to hear. I want to use my wireless headphone. Can anyone help me. thanks