Very suddenly, my Roku Express started playing all audio with a high-pitched tinny noise. I had been watching TV and switched to YouTube when I first noticed it. I thought it was my TV so I tried it on a different TV with no audio issues: same problem. I tried a new HDMI cord. Same problem. Different HDMI port didn't help. I tested it with YouTube, Sling, and Hulu and all had the same sound. On my Playstation 4, the sound is crystal clear on youtube and Hulu.
I'm not sure what my options are. I've only had the Roku since November and it's been fine until now. Even this morning was okay. It wasn't until I switched from Sling to YouTube that the sound went bad. Going back to Sling gave the same sound.
As I said, I've tested it on multiple tvs. One Samsung, one Sceptre, and my Sony SmartTV. It's definitely the Roku.