Please also see thread: "Major audio issues with roku ultra" as this is very much the exact same issue.
I have a background in computer engineering and I know enough about circuit design to have a brief understanding about what's going on.
Imagine a battery, the longer that the battery is on, the lower the power, the lower your sound. Eventually it will stop working entirely and go mute or just make a horrific audio noise as the signals are no longer working properly. This is what's going on in the roku ultra audio circuit and I will express, vehemently, about how horrific the sound quality and functionality is across the board on these devices. I have a soundbar and it was a game changer because I could hear words!
So... I have experience on this issue over the past ~5+ years on multiple devices and most recently this issue is prevalent.
In order to "reset" the sound circuit, turn the volume on the TV down to very low... go into the roku home screen, system, restart the roku. This will force the roku to add a little charge and the sound might function a little better for the next hour or so. It's something to the point where I have to do this several times a day and it is such an issue with the sound quality in general that I am seriously considering no longer using roku as a product.
I am not biased into any other product, because I believe roku does an amazing job, but I think this issue of poor audio design has been sitting around the devices for so long that it's basically unacceptable. They haven't changed it much or at all since the roku 2 days.
