Hi,
I've a similar problem with my Core i5-4570S on an Asrock Z87E-ITX (Windows 8.1) connected to a Denon AVR via HDMI. Although I updated the BIOS and the Intel drivers the audio signal is lost every time I pause a video (doesnt matter if I pause a video on youtube or while using VLC). To reactivate the audio I have to restart either the AVR or change the configuration of the audio-device in Windows (from 24bit, 192kHz to something else). So, the bitstream has to be reinitialized to make it work again. Very annoying... any advices?