On my upconverting DVD player, you need an audio connection which is separate from the HDMI connection. Therefore, you will need typical red and white audio connections and somewhere to plug in the audio (TV or stero tuner). In addition, in order for the HDMI connection to work propoerly, you will need to set it to the right video method. If you don’t it will not work correctly. On my Toshiba model, I needed to set it to “component” in order to play the correct colors.
I have a Panasonic DVD player that upconverts to HD via HDMI, but I use the optical digital audio connection to my sound system and turn off the audio to the TV. You shouldn’t have to use the audio via the HDMI interface.