If this was a local or locals, someone was likely running around town with hearing difficulty for a few days. A handgun has a level of about 165 decibels. For comparison, a jet engine on takeoff clocks in at about 140 decibels. A firearm discharged indoors is going to affect the shooter right away, much less 32 shots later.
I've seen talk about silencers maybe being used to suggest why others didn't hear the gunfire. Technically, 'silencer' is a misnomer. I disike that the term is used at all my mainstream media because it gives the reader/viewer a false sense of what we're talking about.
Suppressor is a much more accurate term because the attachment suppresses the sound but it comes nowhere near silencing it. A suppressor can lower the sound 10-20 decibels or so. So, we're still talking as loud as a jet engine on takeoff. People inside the house are definitely going to hear it, and people outside will too. It will be muffled somewhat by any insulation a home may have, but it's still going to be very noticeable.
Movies, tv, etc., portray suppressors/silencers as being like the volume of a whisper. So, that's what many people think it is. The truth is, you can only dampen the sound a small amount. You could also purchase subsonic ammunition, which will decrease the sound a bit further, but it's still going to be loud.
Anyways, the shooters. Suppressors or not, firing off that many bullets in an enclosed space is going to have an immediate effect on their hearing from the first shot. Firing multiple shots indoors without hearing protection, very possible permanent hearing damage. At best, a couple of days with reduced hearing. Like the equivalent of going to a rock concert and stand right in front of the speakers.
There is a possibility that the intruder(s) used hearing protection, as one would normally do at the range when target shooting. The problem with that is, it compromises the ability of the shooter(s) to hear what is going on around them, including the possibility that someone nearby has heard the shots and come to the house to investigate.
Would amateurs think of these things? Probably not, though possibly. Pros definitely would.
