S2419HN, Latitude via HDMI, no audio

I recently purchased this S2419HN and have successfully linked the screen output from my Dell Windows 10 Latitude (fully patched) via HDMI. I cannot get any audio output. I've tried connecting the jack from the Latitude and tried both HDMI ports. I've attempted to load the Dell monitor driver however windows does not accept it and prefers it's default. Should it be necessary to use the jacks and the HDMI? I've tried connecting other sound devices (mobile phone) via the jack but there is still no sound. Have I bought a defective S2419HN?