Hello huggie00 :smileyhappy:
Welcome to the HP Forums!
I understand the HDMI connection you configured does not produce any sound. I will do my best to assist you! First, please clarify whether or not this occurs on other programs, besides Netflix. Additionally, please provide the following information:
1. The computer's model number. If you require assistance locating this information, please reference this website: Guide to finding your product number
2. The computer's operating system. If you require assistance locating this information, please reference this website to determine your Windows operating system.
3. Have you installed any new hardware on this computer, before the issue appeared?
4. Have you installed any new software or drivers on this computer, before the issue appeared?
Thanks for bringing this issue to the HP Forums. Have a great day! 
Mario