I stand corrected! I am, in fact, getting audio on the television that is connected to the HD60 S+ devices HDMI out port! So, it appears as though the audio problem is confined to the laptop and OBS Studio. It has occurred to me that the issue might be about the USB port to which I'm connecting the Elgato. I believe it's supposed to be USB3. I believe that I'm using a USB3 port. Unfortunately, on my laptop, those ports are not labeled. According to the literature, however, those ports are supposed to be USB3. When I tried using a different USB port, there is a noticeable degradation in performance.
Okay. I've said a lot without contributing much towards a solution. I'm just hoping that, collectively, we can figure this out.