Public Test in-game SFX not working properly?

For some reason when playing in the public test, the sounds are muffled and weird. The footsteps sound like you are dragging a chain behind you. There are similar sounds with nature/animal sfx. In the main menu they all come out right, but in game they don’t.

I was playing in single player, Wild Start, no barbarians. (No mods and the rest set to default)

I initially started with the output audio at: 24 Bit 48000 Hz, when I changed to 24 Bit 44100 Hz there was no change.

https://youtu.be/YhjAU2YjpCw

PC Specs:

Windows 7 Pro SP1 64Bit

Motherboard: Asus Z170 Pro Gaming Motherboard (small problem with initial start-up - USB's don't work, after reset they do?)

CPU: Intel Core I7-6700K Processor (4 GHz, 8 M Cache, LGA1151)

Heatsink: Noctua NH-U14S Ultra-Quiet Slim CPU Cooler with NF-A15 Fan

RAM: 32GB DDR4 3000MHZ Corsair Vengeance

PageFile: 64GB

GPU: Sapphire Radeon NITRO R9 390 OC Gaming GPU 8GB

1st HD: 240GB Radeon SSD

2nd HD: 2TB SATA III

3rd HD: 2TB SATA III

4th HD: 240GB Kingston SSD

5th HD: 2TB SATA III

Optical Drive: Pioneer BD-RW BDR-209

Sound Card: Sound Blaster Zx

PSU (Power Supply): Corsair RM1000i RMi Series 1000 Watt Fully Modular Power Supply

Monitor: (1st): IIYama 28" G-Master GB2888UHSU Monitor (3840 x 2160 Max DPI)

Mouse:Tecknet 6D Gaming Mouse (Cheep but still a good mouse)

Keyboard: Corsair Raptor K30