How many channels are you trying to extract? What level of HDMI is needed? Are you needing HDMI pass through with audio extraction, or do you already have the HDMI split? Or are you trying to use ARC to then go to an HDMI extractor to then feed to speakers?
I apologize, but I would like to know more information on what your planned setup is in order to even be able to search for an audio extractor that meets your needs. Additionally, is this going into a speaker like a soundbar? If so, then you can shell the audio extractors or might look at a finished product like that at parts express. For example, this soundbar kit. https://www.parts-express.com/Dayton-Audio-SBA302-BT-Sound-Bar-Amplifier-Kit-with-BT-and-IR-Remote-300-880
So I agree with the others, but would need more info to give a solid recommendation for devices with specific features.