I had the same issue, it was because of core isolation drivers. If you update Hx edit i think it install the 2.0 driver wich require core isolation and memory integrity to work.
As i couldn't activate memory integrity here is what i did.
Check device manager for Helix audio driver (should probably show a yellow sign ) : right click and uninstall device, check the box for uninstalling associated driver.
Reboot and install 1.97 driver, the yellow sign should diseapear and sound should be back.