So what if you want to listen to headphones in this modern HDMI connected world?
There were some old converters, but they only decoded 2.1 sound. Here’s one that decodes 2.1 or 5.1 sound. 2.1 sound is not going to be enough. Most broadcasts these days are 5.1 or 7.1 and most Set Top boxes and BluRay can be dumbed down to 5.1, but probably not 2.1.