I recently purchased some amplified earmuffs to use in a HD situation (if time permits.) It would be the last thing I'd worry about but want the option available. I have multiple layers of protection that "should" give me adequate time to put them on.
As for their effectiveness, I just took them to an indoor range this week to try them out. I had them amplified so I could hear normal sounds. Then, before I could get a round off with my HD shotgun, a guy two lanes over unleashed a hellishly loud full-auto rifle. (The range rents full-autos). Although it was not deafening, it still was not very comfortable. I don't think those amplified muffs were designed to handle full-auto rifles. When he ran out of ammo I quickly put in my foam plugs as well.
However, I figure if those amplified muffs made an extremely loud full-auto rifle endurable then they should work fine in a HD situation. Again, they would be the last thing I went for after arming myself.
I completely agree with you on this scenario. People often underestimate how loud gunfire is indoors without hearing protection. Unfortunately, I had a friend test out the remodeling capabilities of his Mossberg 590 on my ceiling. Turns out they are quite effective at installing sky lights. But! after it went off I could barely stand because I was so dizzy. It felt like the room was pulsating for a solid 10 minutes.
The reason why I am a proponent of HD hearing protection is because it gives you an advantage over the bad guys and any instance that you can quickly get an edge over the bad guy(s) is worth investigating.
People often overlook the concussive properties of sound as it is an energy-containing wave. Yes, it will hurt your eardrums but it will also impair your balance like in my case. Balance is maintained mainly through 3 signal inputs: sight, proprioception (sensory cells in muscles, tendons, and ligaments that help interpret your position in space), and vestibular (in your ears). Typically, you'll need two of those functioning at any given time to have proper balance. In most HD scenarios, it will be dark so that is one strike against your balance, which means you will definitely need the other two working at their max capabilities. Shooting a gun indoors without hearing protection will most definitely disrupt the vestibular input for balance, which will be strike two.
Of course, in the proirity of events, if somone comes kicking in my bedroom door before I heard them enter the house then I would grab my firearm first. But in that case, if you didn't hear them already you may not need the hearing protection anyways

All in all, when I practice HD scenarios I always incorporate my hearing protection. If I have time to grab my weapons, I'll have time for putting on my hearing protection.