The yellow is for video. All you need to hook up is the red and white for sound! BTW, you might only need a miniplug adapter to use headphones on the new TV!
Adapter for Headphones
Trying to assist an elderly family member. Have a pair of headphones that they use for the television that amplifies the sound so that they can hear without turning up the volume and deafening everyone else. Got a new tv which no longer has the place to plug in the red and white RCA inputs. Is there such a thing as an HDMI/RCA adapter? I've looked on Amazon and they sell lots of gaming ones that also have a yellow jack. Would this work? TIA