It appears to have addressed an issue I was having with Dolby Atmos being silent when trying to watch episodes of Prehistoric Planet. When trying to watch the first three episodes there was no sound at all. However, after I selected a different show to watch sound would return and then I could go back to the Prehistoric Planet episode and sound would work there too. Odd behavior that I never encountered until after updating to 15.5. 15.5.1 seems to have fixed that issue.