NO AUDIO FROM MY MONITOR -- ACER H236HL

I am running Windows 10. I have an ASUS ROG computer. In the past I have simply plugged an HDMI cable into my computer and monitor and the two spoke to each other very well. Today, I am trying to demonstrate something to a client and I have no sound coming from my monitor. The picture is perfect. All of the computer outputs SAY that it is playing out to ACER H236HL. The output levels are good. I have checked the device driver and it is a Generic PnP. No Acer. I checked the driver repository too and there is no acer driver in there either. Even if I had found one, I would not know how to implement it. HELP!