Some claimed the KB4515384 update reset all of their audio settings, others said it led to playback issues while playing games and still others said it caused issues with noise levels. These problems appear to vary from person to person.
Windows Latest then discovered that numerous people have complained about the KB4515384 cumulative update causing issues with audio.
Microsoft released the update on September 10, and by September 12, it was clear the update had failed to address the Windows Desktop Search problems it was specifically made to fix. The complaints about the most recent Windows 10 update haven't stopped. This may result in games sounding different than customers are used to and may have missing channels.' Due to customer feedback, we are reverting this change as some games and some devices are not rendering multi-channel audio as expected. At the request of some of our audio partners, we implemented a compatibility change that enabled certain games to query support and render multi-channel audio. 'Microsoft has received reports that audio in certain games is quieter or different than expected after installing this update.