I had signed up and installed the iOS 9.2 beta (versions 3 & 4) on my 6s to see if it would remedy the scratchy speaker I was experiencing with some apps. I reported the problems via the Feedback app that gets installed on your device when you download the beta. I didn't hear anything from Apple initially, but just today received this from them: "Engineering has implemented changes that are supposed to fix the problem you reported. These changes are in the latest version of the software available to you, 13D11." I deleted the beta off my phone when iOS 9.2 officially dropped to the public and haven't given much thought about it since, but I'm considering downloading the 9.2.1 beta now if it really does remedy the speaker issue. Can anyone confirm?