Listening to the Stone Cold podcast, the issue came up. Apparently a lot of people who 'were there' [citation needed] say that the building has famously shite acoustics, but that seems like BS. You could hear 'em for Cena, and the occasional folks shouting 'Boooooring' during Goldust/Stardust rang out clear as a bell.
Podcast mentioned something else - you can normally tell the temperature of the crowd, even with the sound on mute, from heir body language and it's true, the crowd looked a little disengaged. Not saying I blame them tbh, most of the card was like something you'd see on RAW most weeks, but Sting getting a weak pop was little eye-opening.