I came up with a workaround for this today. You can use an headphone-->rca cable. You can plug it in, or possibly the newer technology audio hdmi adaptor that combines the two into the headphone jack, and then into rca.
The trick is you then need to tell the TV that while you are using the HDMI for video, you need it to use a different input for audio. (in my case video 2). In the case of my Panasonic TV Menu-->Audio-->Advanced AudioTV Menu-->Audio-->Advanced Audio
, and then arrow down to the hdmi video input you're using and then arrow to the side to make a different selection.