My first job would be to ensure that my family and myself survive. I'd pick the tool that best helps me accomplish that task and then worry about the noise.
The argument against that logic is that in one study (linked elsewhere on this site, and you'll notice my rounding fudges the total to 101%) showed that 55% off attacks are commited by 2 people, 25% by 1, 20% by 3, and 1% by 4 or more. Which means more than 75% of the time, there is at least one other person involved. If your hearing is impaired after stopping the first assailant, you might not hear the second.
The counterarguments are of course that you can have hearing protection available, and that the overall difference in decible isn't that much. Can't rebut to the first counter (electronic hearing protection still lets you hear what's going on) but you can talk about sound duration and the direction of the blast with a muzzle brake.
Overall, though, I agree with you - the sound is a secondary concern for me. However, I also don't think you give up much by having a shotgun instead of an AR. My primary HD weapon right now is a shotgun.